A boy and a girl are playing in a park. The only daughter of the maternal grandfather of the girl, is the sister of the boy's father. How is the boy related to the girl?

Answer: D. Cousin

Official answer key verified. Detailed explanation coming soon.

Source: SSC CHSL (Tier-1) 2016 Online Exam Paper held on 11 January 2017, Evening Shift (General Intelligence) — SSC-published paper with official answer key, via sscportal.in (note: image files on the Quantitative Aptitude page are named 08-Jan-2017, likely an sscportal upload-label error; page titles and QID sequence 201-300 consistently indicate 11 Jan 2017 Evening Shift) · official-answer-key