The increasing order of the rate of HCN addition to compounds A – D is (A) HCHO (B) CH3COCH3 (C) PhCOCH3 (D) PhCOPh

Question

The increasing order of the rate of HCN addition to compounds A – D is
(A) HCHO
(B) CH₃COCH₃
(C) PhCOCH₃
(D) PhCOPh

A < B < C < D