Question: Saturday Night Live's 40th season premiered with which American actor as the first host?

Context paragraphs:
The Boston Teens: The Boston Teens are fictional characters featured on the American television show "Saturday Night Live".  "The Boston Teens" debuted in 1999 and have appeared in 13 sketches to date. " TV Guide" named The Boston Teens among "Saturday Night Live"' s 40 greatest characters in a list compiled in honor of the show's 40th anniversary in 2015.

A Night at the Roxbury: A Night at the Roxbury is a 1998 American comedy film based on a recurring skit on television's long-running "Saturday Night Live" called "The Roxbury Guys".  "Saturday Night Live" regulars Will Ferrell, Chris Kattan, Molly Shannon, Mark McKinney and Colin Quinn star.  This film expands on the original Saturday Night Live sketches where the Roxbury Guys were joined by that week's host, and bobbed their heads to Haddaway's hit song "What Is Love" while being comically rejected by women at various clubs.

Chris Pratt: Christopher Michael Pratt (born June 21, 1979) is an American actor.  Pratt came to prominence with his television roles; he is best known for his roles as Owen Grady in "Jurassic World", Jim Preston in "Passengers" and Andy Dwyer in the NBC sitcom "Parks and Recreation" from 2009–2015, for which he received critical acclaim and was nominated for the Critics' Choice Television Award for Best Supporting Actor in a Comedy Series in 2013.  He also starred earlier in his career as Bright Abbott in The WB drama series "Everwood" (2002–2006).  His early film career began with supporting roles in such mainstream films as "Wanted" (2008), "Jennifer's Body" (2009), "Moneyball" (2011), "The Five-Year Engagement" (2012), "Zero Dark Thirty" (2013), "Delivery Man" (2013), and "Her" (2013).

Wayne's World: "Wayne's World" was originally a recurring sketch from the NBC television series "Saturday Night Live".  It evolved from a segment titled "Wayne's Power Minute" (1987) on the CBC Television series "It's Only Rock & Roll", as the main character first appeared in that show.  The "Saturday Night Live" sketch spawned two films, and several catchphrases which have since entered the pop-culture lexicon.  The sketch centered on a local public-access television program in Aurora, Illinois, hosted by Wayne Campbell (Mike Myers, the same actor from "Wayne's Power Minute"), an enthusiastic and sardonic long-haired metalhead, and his timid and sometimes high-strung, yet equally metal-loving sidekick and best friend, Garth Algar (Dana Carvey).  Wayne lives with his parents and broadcasts his show "live" from the basement of their house every Friday evening at 10:30.  The first "Wayne's World" sketch appeared in the 13th "Saturday Night Live" episode of 1988/1989.

Saturday Night Live 40th Anniversary Special: The Saturday Night Live 40th Anniversary Special is a three-and-a-half-hour prime-time special that aired on Sunday, February 15, 2015, on NBC, celebrating "Saturday Night Live"' s 40th year on the air, having premiered on October 11, 1975, under the original title "NBC's Saturday Night".  This special generated 23.1 million viewers, becoming NBC's most-watched prime-time, non-sports, entertainment telecast (excluding Super Bowl lead-outs) since the "Friends" series finale in 2004.  It is the third such anniversary special to be broadcast, with celebratory episodes also held during the 15th and 25th seasons.

Ellen Cleghorne: Ellen Cleghorne (born November 29, 1965) is an American actress and comedian, best known as a cast member of "Saturday Night Live" from 1991 to 1995.  Cleghorne was the sketch comedy show's second African-American female repertory cast member, succeeding Danitra Vance in its eleventh season, and the first African-American female cast member to stay for more than one season.  She returned for its 40th anniversary special on February 15, 2015.  Cleghorne was ranked the 69th greatest "Saturday Night Live" cast member by "Rolling Stone" magazine.

SNL Studios: SNL Studios is a production company, founded in July 1997 as a joint venture between "Saturday Night Live" executive producer Lorne Michaels and NBC Studios (now Universal Television, the production arm of NBCUniversal).  While this venture also initially included Paramount Pictures, it was dissolved following NBC's merger with Universal Studios.  On the television side, SNL Studios produces "Saturday Night Live" in association with Broadway Video.  Film productions, typically offshoots of Saturday Night Live' sketches, include, among others, "A Night at the Roxbury" and "Superstar".

Saturday Night Live (season 40): Saturday Night Live premiered its fortieth season during the 2014–15 television season on NBC.  The season premiered on September 27, 2014, with host Chris Pratt and musical guest Ariana Grande and came to a conclusion on May 16, 2015 with host Louis C.K. and musical guest Rihanna.  Former cast member Darrell Hammond succeeded Don Pardo, who had died in August, as the show's new announcer.  The premiere included an interstitial photograph of Pardo – "SNL"' s announcer since it premiered in 1975 (with the exception of season 7 and episode 14 of season 21 – where Hammond took his place).

List of Saturday Night Live episodes: <section begin=head />"Saturday Night Live" ("SNL") is a late-night sketch comedy and variety show created by Lorne Michaels.  It premiered on NBC, a terrestrial television network, on October 11, 1975 under the title "NBC's Saturday Night".  The show often satirizes contemporary American popular culture and politics.  "Saturday Night Live" features a two-tiered cast: the repertory members, also known as the "Not Ready for Prime-Time Players," and newer cast members, known as "Featured Players."  Each week, the show features a host, often a well-known celebrity, who delivers an opening monologue and performs in sketches with the cast.  A musical guest is also invited to perform several sets (usually two, and occasionally more).  Every so often a host or musical guest will fill both roles, such as was the case with Britney Spears in 2000 and 2002, Jennifer Lopez in 2001 and 2010, Justin Timberlake in 2003, 2006 and 2013, Taylor Swift in 2009, Bruno Mars in 2012, Lady Gaga in 2013, Miley Cyrus in 2013 and 2015, Drake in 2014 and 2016, Blake Shelton in 2015, and Ariana Grande in 2016.  With the exception of Season 7 and several other rare cases, the show has begun with a cold open that ends with someone breaking character and proclaiming "Live from New York, it's Saturday Night! "

Celebrity Jeopardy! (Saturday Night Live): Celebrity Jeopardy! is a series of sketches that aired regularly on the television comedy/variety show "Saturday Night Live" between 1996 and 2002, the years when Will Ferrell was a cast member.  It parodies the same-named special event on the television quiz show "Jeopardy!" that features competition between notable individuals with all winnings going towards charitable organizations, and significant reductions to the game's level of difficulty.  Fifteen sketches aired between December 1996 and February 2015: two sketches per season from 1996 to 2002, when Ferrell was a regular on the show; and one each in 2005 and 2009, when Ferrell returned to the show as host.  The sketch was revived for the "Saturday Night Live 40th Anniversary Special" on February 15, 2015.

Supporting paragraphs: Saturday Night Live (season 40) Chris Pratt
Answer: Christopher Michael Pratt