Question: What character did Sarah Chalke play on the most watched television show in the United States from 1989 to 1990?

Context paragraphs:
Roseanne: Roseanne is an American sitcom that was broadcast on ABC from October 18, 1988, to May 20, 1997.  Lauded for its realistic portrayal of the average American family, the series stars Roseanne Barr, and revolves around the Conners, an Illinois working-class family.  The series reached #1 in the Nielsen ratings, becoming the most watched television show in the United States from 1989 to 1990.  The show remained in the top four for six of its nine seasons, and in the top twenty for eight seasons.

Modern history of American football: The modern history of American football can be considered to have begun after the 1932 NFL Playoff game, which was the first American football game to feature hash marks, the legalization of the forward pass anywhere behind the line of scrimmage, and the movement of the goal posts back to the goal line; it was also the first indoor game since 1902.  Other innovations to occur in the years after 1932 were the introduction of the AP Poll in 1934, the tapering of the ends of the football in 1934, the awarding of the first Heisman Trophy in 1935, the first NFL draft in 1936 and the first televised game in 1939.  Another important event was the American football game at the 1932 Summer Olympics, which combined with a similar demonstration game at the 1933 World's Fair, led to the first College All-Star Game in 1934, which in turn was an important factor in the growth of professional football in the United States.  American football's explosion in popularity during the second half of the 20th century can be traced to the 1958 NFL Championship Game, a contest that has been dubbed the "Greatest Game Ever Played".  A rival league to the NFL, the American Football League (AFL), began play in 1960.  In 1966, the NFL initiated the AFL–NFL merger between the two leagues.  The merger lead to the creation of the Super Bowl, which has become the most watched television event in the United States on an annual basis.

Baywatch: Baywatch is an American action drama series about the Los Angeles County Lifeguards who patrol the beaches of Los Angeles County, California, starring David Hasselhoff.  The show was canceled after its first season on NBC, but survived through syndication and later became one of the most watched television shows in the world.  The show ran in its original title and format from 1989 to 1999.  From 1999 to 2001, with a setting change and large cast overhaul, it was known as Baywatch: Hawaii.

Bade Achhe Lagte Hain: Bade Achhe Lagte Hain (English: "It Seems So Beautiful" ; Hindi: बड़े अच्छे लगते हैं ; ] ) is a Hindi-language Indian television soap opera which was broadcast by Sony Entertainment Television India from 30 May 2011 to 10 July 2014, when it ended its run after telecasting 644 episodes.  Based on the Gujarati play "Patrani" by Imtiaz Patel, the soap opera was created by Ekta Kapoor and was produced by her production company Balaji Telefilms.  The name of the soap opera, along with its title track, has been inspired by a song of the same name, composed by R.D. Burman, from the soundtrack of the 1976 Bollywood film "Balika Badhu".  Ekta Kapoor had got the name, "Bade Achhe Lagte Hain", registered about six years before the soap opera premiered.  "Bade Achhe Lagte Hain" is the seventh most watched television show of 2011, in India.

Sarah Chalke: Sarah Chalke ( ; born August 27, 1976) is a Canadian actress.  She is known for portraying Dr. Elliot Reid on the NBC/ABC comedy series "Scrubs", the second Rebecca "Becky" Conner on the ABC sitcom "Roseanne", Stella Zinman on the CBS sitcom "How I Met Your Mother", and Beth Smith on Adult Swim's adult animated science-fiction series "Rick and Morty".  She also had a recurring role on the third season of the ABC/TBS sitcom "Cougar Town".

Daughters (film): Daughters, also known as Our Mother's Murder is a 1997 made-for-TV drama film directed by Bill L. Norton, and stars Holly Marie Combs and Sarah Chalke who play Alex and Annie, the two eldest daughters of the main character Anne.

Undercover Angels: Undercover Angels was a 2002 Australian television series produced by the Seven Network which imitated the American "Charlie's Angels" series.  It featured multiple Olympic and World champion swimmer Ian Thorpe, who acted as the mentor to three women (Jackie O, Katie Underwood and Simone Kessell) who performed good deeds for people in need.  The show was first shown on 12 May, and was the fifth most watched television show in that week in Australia.  Overall, it averaged 1.3 million viewers in its run of eleven episodes.

KidZone: KidZone is a Canadian TV show for adolescents that aired on Knowledge in British Columbia from 1989 to 2001.  The show is also notable for providing a start for several young stars, including Sarah Chalke, Devon Sawa, Erica Cerra, Jai West, Kea Wong and Taheer Mohamed.

List of House Husbands episodes: "House Husbands" is an Australian television comedy-drama, created by writers Ellie Beaumont and Drew Proffit.  It centres on four families where the fathers – Lewis (Gary Sweet), Mark (Rhys Muldoon), Kane (Gyton Grantley) and Justin (Firass Dirani) – are in charge of raising the children.  The first ten-part series premiered on the Nine Network on 2 September 2012.  The drama set a ratings record for the network and became Australia's most watched television show.  On 23 September, it was announced that Nine had renewed "House Husbands" for a second season.  It began airing from 8 April 2013.  A third season was broadcast in 2014 and fourth began airing from 10 August 2015.

The 'Bu (TV show): The 'Bu is a 2003 award-winning television series from Channel 101's short film contest, it mocks the soap opera television genre and satirized life in Malibu, California (hence the reference to "the 'bu" as a slang name for Malibu) and has seven finished episodes, with an eighth episode "apology" also submitted after the creators ended the show.  It was created by The Lonely Island, it stars Andy Samberg, Jorma Taccone and Sarah Chalke, and was directed by Akiva Schaffer.  The group's website references the show as "vintage" and cites it as an example of their early work.  Three more episodes were filmed after the original cast abandoned the series, bringing the total number of episodes to 11 but it was cancelled in April 2005.

Supporting paragraphs: Sarah Chalke Roseanne
Answer: the second Rebecca "Becky" Conner