Question: What is the offcial name of the cup which an annual knockout football competition and Crewe Alexandra'swill also participate along with competing in League Two?

Context paragraphs:
EFL Cup: The EFL Cup (referred to historically, and colloquially, as simply the League Cup), currently known as the Carabao Cup for sponsorship reasons, is an annual knockout football competition in men's domestic English football.  Organised by the English Football League (EFL), it is open to any club within the top four levels of the English football league system – 92 clubs in total – comprising the top level Premier League, and the three divisions of the English Football League's own league competition (Championship, League One and League Two).

FA Cup: The FA Cup, known officially as The Football Association Challenge Cup, is an annual knockout football competition in men's domestic English football.  First played during the 1871–72 season, it is the oldest association football competition in the world.  It is organised by and named after The Football Association (The FA).  For sponsorship reasons, from 2015 through to 2018 it is also known as The Emirates FA Cup.  A concurrent women's tournament is also held, the FA Women's Cup.

Francis Tierney: Francis Tierney (born 10 September 1975) is a retired English professional footballer who played most notably for Crewe Alexandra and Doncaster Rovers.  Tierney came through the famous Crewe Alexandra academy system where he was extremely highly rated by Dario Gradi, and the coaching staff.  He played as a winger or striker, and was known for his dribbling skills and technique.  Tierney played almost 100 times for Crewe in the bottom two divisions, scoring 11 times.  He was an important part of the team that won promotion from League 2 to League 1 in 1994–95, and also played 22 times in the Crewe side that won promotion via the Play-Offs from League 1 to The Championship in 1996–97.

2015 Chatham Cup: The 2015 Chatham Cup is New Zealand's 88th annual knockout football competition.

2017–18 Crewe Alexandra F.C. season: The 2017–18 season is Crewe Alexandra's 141st season in their history and second consecutive in League Two.  Along with competing in League Two, the club will also participate in the FA Cup, EFL Cup and EFL Trophy.

2017 Chatham Cup: The 2017 Chatham Cup (known as the ISPS Handa Chatham Cup for sponsorship reasons) is New Zealand's 90th annual knockout football competition.

Nick Powell: Nicholas Edward "Nick" Powell (born 23 March 1994) is an English professional footballer who plays for Wigan Athletic as a midfielder.  He began his career at Crewe Alexandra, initially as a forward, making his debut at the age of 16.  After impressing for Crewe Alexandra during the 2011–12 season, including scoring in their 2–0 victory in the League Two play-off Final, he moved to Manchester United in July 2012.  Unable to break into the Manchester United first team, however, he went on loan to Wigan Athletic, Leicester City and Hull City before being released in June 2016.  He joined Wigan Athletic in July 2016.  He has represented England at under-16, under-17, under-18, under-19 and under-21 levels.

2013 Football League Trophy Final: The 2013 Football League Trophy Final was the 30th final of the English domestic football cup competition for teams from Football Leagues One and Two, the Football League Trophy.  The final was played at Wembley Stadium in London on 7 April 2013.  The match was contested between Crewe Alexandra from League One and Southend United from League Two.  Crewe Alexandra won the game 2–0, following goals from Luke Murphy and Max Clayton.

Iraq FA Cup: The Iraq FA Cup (Arabic: كأس العراق) is an annual knockout football competition in men's domestic Iraqi football.  First held in the 1975–76 season, it is organised by and named after the Iraq Football Association.  The tournament begins with two rounds played between lower division clubs, twelve of which advance to the Round of 32, where the Iraqi Premier League clubs are entered.  The Round of 32 is then followed by the Round of 16, the quarter-finals, the semi-finals and the final, with all rounds being single legs (draws are decided by penalties if necessary; extra-time is not played).

2016–17 Crewe Alexandra F.C. season: The 2016–17 season is Crewe Alexandra's 140th season in their history and first back in League Two following relegation the previous season.  Along with competing in League Two, the club will also participate in the FA Cup, League Cup and Football League Trophy.

Supporting paragraphs: 2017–18 Crewe Alexandra F.C. season FA Cup
Answer: The Football Association Challenge Cup