The correct option is A Bhai Lehna
Guru Nanak appointed Bhai Lehna as the successor Guru in 1539, renaming him as Guru Angad. Guru Angad had given up his own faith and instead had become a Sikh. He served and worked with Guru Nanak for many years. Having tested his discipleship through several tests over the years, Guru Nanak designated him as Guru Angad, the second guru of the Sikhs.