An oocyte is fertilized in the a. vagina. b. uterus. c. oviduct. d. ovary.

The female reproductive system consists of several organs, including the vagina, uterus, oviduct (also known as the fallopian tube), and ovary. The role of the reproductive system is to enable the production of offspring through the process of fertilization.

Fertilization occurs when a sperm cell from a male combines with an egg cell (oocyte) from a female. The sperm cell travels through the female reproductive system to reach and fuse with the oocyte, resulting in a fertilized egg.

Let's go through each option given in the exercise: a. Vagina: The vagina is a muscular canal that serves as the entrance to the female reproductive system. While sperm cells are deposited into the vagina during sexual intercourse, fertilization does not occur here. b. Uterus: The uterus is a muscular, pear-shaped organ where the fertilized egg implants and develops into a fetus. However, fertilization does not take place inside the uterus. c. Oviduct: The oviduct, also known as the fallopian tube, connects the ovary to the uterus. The oocyte travels from the ovary to the oviduct, where it may encounter sperm cells. Fertilization typically occurs within the oviduct. d. Ovary: The ovary is the organ responsible for producing oocytes (female egg cells) and female hormones. While oocyte maturation and release occur in the ovary, fertilization does not.

After reviewing each organ in the female reproductive system and understanding the process of fertilization, it is clear that the correct answer is c. Oviduct. This is where the oocyte encounters and fuses with a sperm cell, leading to fertilization.