Final answer:
The fallopian tubes are approximately 10 centimeters long, which is necessary for the journey and potential fertilization of the egg before it reaches the uterus.
Step-by-step explanation:
The fallopian tubes are part of the female reproductive system and play a crucial role in fertility and conception. The fallopian tubes, also known as oviducts, extend from the uterus to the ovaries. Although they are located near the ovaries, they are not physically attached to them. The end of the fallopian tube closest to the ovary has fringe-like structures called fimbriae, which help guide the egg from the ovary into the tube. Once inside the fallopian tube, the egg may be fertilized by sperm, with fertilization typically occurring within the tube. The ciliated walls and smooth muscle contractions of the fallopian tubes facilitate the movement of the egg or the fertilized embryo towards the uterus for implantation. To answer the student's question, fallopian tubes are approximately 10 centimeters long, which is the correct answer and corresponds to option (a) 10 cm. This length allows enough space for the egg to be fertilized and start its journey towards the uterus.