Successful fertilization of the secondary oocyte usually occurs:
a) within 15 minutes of sexual intercourse.
b) two weeks following ovulation.
c) in the ovary.
d) in the upper third of the uterine tube.
e) in the uterus

The correct answer will be option-D

Explanation:

Uterine tube or oviduct or the fallopian tubes are the long, narrow tube in the abdominal cavity of the female reproductive system.

The uterine tube help transport the sperms to reach the ovum, It connects the ovary to the uterus and provides the suitable medium for the fertilization to occur.  

The fertilization does not take place in the uterus and the ovary but in the uterine tubes.

The fertilization does not take place just after 15 minutes of sexual intercourse as the sperms get killed in the cervical canal and the once which remains alive is transported by the uterine contractions which start after 30 minutes.

Thus, option-D is the correct answer.