Question

a sperm and egg come together to make a single cell called a
bathtub - grown pony
reproduction
zygote
fetus

Explanation:

Fertilization occurs when a sperm and an egg fuse. The resulting single - cell is called a zygote. A bathtub - grown pony is a non - biological and fictional concept. Reproduction is the overall process, not the name of the cell formed. A fetus is a later - stage of development after the zygote has undergone multiple cell divisions and differentiation.

Answer:

C. zygote