Solution:
Acidity D > A > B > C.
Minus I effect is the factor.
Acidity increases if
1. More minus I effect is present.
2. The resulting ion is stable.
3. The proton is donated fast.
4.Conjugate base must be stable.
The general order of acidity is,
RCOOH>Phenol>Water>Alcohols>yne>ene>ane.
