NEET Biology question

...A... is a binomial expression of (*p*+*q*)2. When frequency measured, differs from the expected values, the difference indicates the extent of...B... Choose the option for A and B to complete the given NCERT statement

• (A)A−*p*2+2*pq*+*q*2 =1; B-evolutionary changeCorrect
• (B)A−*p*2+2*pq*+*q*2+*q*2 = 1; B-genetic change
• (C)A−*p*2+2*pq*+*q*2 ≥ 1; B-genetic change
• (D)A−*p*2+2*pq*+*q*2 ≤ 1; B-evolutionary change