Q17,Paper2 ,J14. A Boolean function F is called self- dual if and only if F(x1, x2, ...xn) = F(–x1,–x2, ...–xn) How many Boolean functions of degree n are self-dual ?

(A) 2ⁿ

(B) (2)²ⁿ

(C) (2)ⁿ²

(D) ₂^{2^(n–1 )}

Answer D.

This is a theorem,that  ₂^{2^(n–1)} booleans functions are self dual^.