Highest acidic hydrogen possessing group among C_(2)H_(2), C_(2)H_(4), C_(2)H_(6) and C_(2)H_(6) is ………….

Highest acidic hydrogen possessing group among C_(2)H_(2), C_(2)H_(4),

1.	Highest acidic hydrogen possessing group among C_(2)H_(2), C_(2)H_(4), C_(2)H_(6) and C_(2)H_(6) is ………….
Answer» SOLUTION :`C_(2)H_(2)`