[" 33.The second maturation division of the "],[" mammalian ovum occurs "],[[" (a) shortly after ovulation before the ovum "],[" makes entry into.the fallopian tube "],[" by a sperm "],[" by a sperm "],[" (c) until the nucleus of the sperm has fused "],[" with that of the ovum "],[" (d) in the graafian follicle following the first "],[" maturation division "]]