How many of the following structures may be found in fallopian tubes normally?

Secondary oocyte, Primary oocyte, Secondary follicle, Egg, Zygote.

The correct option is C Three
A primary oocyte is produced by the ovary from the oogonia during oogenesis. Secondary oocyte is an oocyte which is produced by the first meiotic division of primary oocyte. It leaves the ruptured follicle and enters the fallopian tube. Here, it is then pushed by cilia towards the uterus. An egg can live in the fallopian tube for about 24 hours. The sperm can travel up through the uterus to the fallopian tube and can fertilize with the egg. The fertilized egg stays in the fallopian tube for about 3 to 4 days. However, the fertilized egg starts dividing after 24 hours. A fertilized egg is called a zygote until it divides into 16 cells and forms a morula. Hence, out of the given structures, secondary oocyte, egg, and zygote may be found in fallopian tubes.

Thus, the correct answer is 'Three.'