To make a positive identification with the help of a partial fingerprint, the points of similarity should be at least -: (A) 10, (B) 12, (C) 16, (D) 20
Answer is C. For this different textbooks have given a different number:-

Parikh  → 16 characteristics
Reddy  →10 - 12 finer characteristics
Seth and Simpson → 16 - 20 characteristics

16 is given in more number of textbooks, so the answer is 16.