Final answer:
Conception is possible during menstruation in a long menstrual cycle because sperm can survive for 3-5 days in the female reproductive tract.
Step-by-step explanation:
Among the options provided regarding conception, the statement that is TRUE is that conception is possible during menstruation in a long menstrual cycle. Sperm can survive within the female reproductive tract for approximately 3-5 days, and if intercourse occurs close to the end of the menstrual period in women with longer cycles, it's possible that ovulation could happen shortly after, and the sperm could fertilize the egg. Statements claiming that fertilization is typically possible 4 days after ovulation or that conception normally happens within 2-4 hours of intercourse are inaccurate, as sperm need time to travel to the oocyte, and the oocyte is only viable for about 24 hours post-ovulation. The assertion that intercourse must be avoided 5 days before and 3 days after menstruation to avoid conception does not completely guarantee the prevention of conception due to cycle variability and the survival time of sperm.