Let $A=PQ$. The elementary operations on A, that produces the same effect as it does on applying on P and keeping Q unchanged is : (A) $R_i↔R_j$ (B) $R_i→R_i+KR_j$ (C) $C_i →K\, C_i$ (D) $C_i → C_i + K C_j $ Choose the correct answer from the options given below :

(A) and (B) Only (A) and (B) and (D)  Only (A) and (C) and (D)  Only (B) and (D) Only

(A) and (B) Only