How does fertilization take place? Fertilization occurs once in a month. Comment.

(N/A) During sexual intercourse,sperm enters through the vaginal passage and moves upwards into the fallopian tube (oviduct).
$(b)$ An egg is released from the ovary and reaches the oviduct.
$(c)$ The sperm encounters the egg in the oviduct,where fusion occurs,resulting in fertilization.
$(d)$ Fertilization occurs once a month because the ovary releases only one egg every month during the menstrual cycle.