Why did actor Imran Khan choose his mother's surname over his father's?

Imran Khan, born Imran Pal, is an American citizen by birth and holds an OCI card. He was born on January 13, 1983 in US, to Anil Pal, a software engineer, and Nuzhat Khan, a psychologist. They parted ways when he was around 2. He chose to take his mother's surname as she was the one who brought him up.