Question: After departing the boy band One Direction, who debuted a studio album with its lead single "Pillowtalk"?
Context: One Direction: Where We Are – The Concert Film, also known as One Direction: Where We Are - Live from San Siro Stadium is the second concert film by English-Irish boy band One Direction and the sequel to "".  The film takes place during the 28 and 29 June 2014 shows of the band's Where We Are Tour at San Siro Stadium in Milan, Italy.  It contains a 15-minute interview with the band with exclusive behind-the-scenes footage. " Midnight Memories" is the third studio album by British-Irish boy band One Direction, released on 25 November 2013 by Columbia Records, Syco Music and Sony Music.  The album was described as having a "slightly rockier tone" than their previous efforts.  It has become the fastest-selling album in Amazon UK's history, breaking the record set by One Direction's previous release, "Take Me Home" (2012).  The album debuted at number one on the US "Billboard" 200, making One Direction the first group in history to debut at number one in the US with their first three albums.  The album was preceded by the release of the singles "Best Song Ever" and "Story of My Life". "Drag Me Down" is a song recorded by English-Irish boy band One Direction for their fifth studio album, "Made in the A.M." (2015).  The song was released worldwide on 31 July 2015 and was the band's first single since Zayn Malik's departure earlier that same year.  "Drag Me Down" debuted atop the charts in the United Kingdom, Ireland, France, Austria, Australia, and New Zealand.  It became the group's first number one single in France and Australia, as well as their fourth number one in New Zealand and the United Kingdom.  It debuted at number three on the "Billboard" Hot 100 chart and won the fan-voted 'Best Video Award' at the 2016 Brit Awards. "Live While We're Young" is a song by English-Irish boy band One Direction, released as the lead single from their second studio album, "Take Me Home" (2012).  Written by Savan Kotecha and its producers, Rami Yacoub and Carl Falk, the number was released by Syco Records on 28 September 2012.  Falk, Kotecha, and Yacoub had collaboratively helmed One Direction's previous hits, "What Makes You Beautiful" and "One Thing".  The track is an uptempo, upbeat bubblegum pop song which features rock undertones, vocal harmonies, hand claps, prominent electric guitar riffs, and repetitive synthesizers.  The chorus of the song is predominantly featured alongside the bridge, and is backed by wordless chants.  Its opening guitar riff bears similarities with The Clash's 1982 single, "Should I Stay or Should I Go". Made in the A.M. is the fifth studio album by the English-Irish boy band One Direction, released on 13 November 2015, by Columbia Records and Syco Music.  The album is the group's first album following the departure of Zayn Malik, who left the group in March 2015.  The album was complemented by the singles "Drag Me Down", released on 31 July 2015; "Perfect", released on 16 October 2015 and "History", released on 16 January 2016.  These three singles reached the top 10 in a number of national charts. Liam James Payne (born 29 August 1993) is an English singer and songwriter.  He rose to fame as a member of the boy band One Direction.  Payne made his debut as a singer when he auditioned for the British television series "The X Factor" in 2008.  After being eliminated as a solo performer, he auditioned again in 2010 and was put into a group with four other contestants to form One Direction.  One Direction has released five commercially successful albums, performed on four worldwide tours, and won multiple awards. "Moments" is a song by English-Irish boy band One Direction from their debut studio album, "Up All Night" (2011).  It was written by Ed Sheeran, and Si Hulbert, the song's producer.  In 2011, as One Direction member Harry Styles told Sheeran that the boy band did not have enough songs for their album, Sheeran offered "Moments" as a track that Sheeran "was never going to use". "Strip That Down" is the debut solo single by English singer and songwriter Liam Payne, featuring guest vocals from American rapper Quavo.  It was released as the lead single for his forthcoming debut studio album on 19 May 2017, via Capitol Records in the UK and Republic Records in the US.  The song was written by Payne, Ed Sheeran—who contributes uncredited vocals to the song, Steve Mac and Quavo.  It was serviced to US contemporary hit radio on 23 May 2017.  The song's accompanying music video was released on 2 June 2017.  The lyrical content is supposed to reflect Payne's freedom to venture into raunchy musical elements after departing from the British-Irish boy band One Direction. Louis William Tomlinson (born Louis Troy Austin; 24 December 1991) is an English singer and songwriter.  He is known as a member of the boy band One Direction.  Tomlinson began his career as an actor, appearing in ITV drama film "If I Had You" and the BBC drama "Waterloo Road".  In 2010, he became a member of One Direction after being eliminated as a solo artist on the British music competition series "The X Factor".  Tomlinson is one of the main songwriters of One Direction's repertoire.  Following the band's hiatus, Tomlinson released the singles "Just Hold On" and "Back to You".  The latter will be included in his debut studio album, which will be released in 2017 by Epic Records. Zain Javadd "Zayn" Malik ( Urdu: ‎ ; born 12 January 1993), who records mononymously as Zayn, is a British singer and songwriter.  Born and raised in Bradford, Malik aspired to pursue a career in music from a young age, and auditioned as a solo artist for the British music competition "The X Factor" in 2010.  After being eliminated as a solo performer, Malik was brought back into the competition, along with four other contestants, to form the boy band that would become known as One Direction.  Malik split from the group in March 2015 and signed a solo recording contract with RCA Records.  Adopting a more R&B music style with his debut studio album "Mind of Mine" (2016) and its lead single, "Pillowtalk", Malik became the first British male artist to debut at number one in both the UK and US with a debut single and debut album.  Malik is the recipient of several accolades, including an American Music Award and a Billboard Music Award.
Answer: Zayn Malik