Assertion (A) states that females play a major role in determining the sex of the offspring. This is false in human beings. Males have sex chromosomes XY, and females have XX. During gamete formation, females produce ova containing only X chromosomes, while males produce sperm containing either an X or a Y chromosome. The sex of the offspring is determined by the type of sperm that fertilizes the ovum: if an X sperm fertilizes, the offspring is XX (female); if a Y sperm fertilizes, the offspring is XY (male). Thus, the male gamete (sperm) determines the sex. Reason (R) states that women have two ‘X’ chromosomes. This is true for typical human females (XX).