Answer the following question given this paragraph: Many animals have a relatively simple life cycle. A general animal life cycle is shown in Figure below . Most animals spend the majority of their life as diploid organisms. Just about all animals reproduce sexually. Diploid adults undergo meiosis to produce sperm or eggs. Fertilization occurs when a sperm and an egg fuse. The zygote that forms develops into an embryo. The embryo eventually develops into an adult. Q: What causes fertilization to occur? A:

Choose your answer from:
A). accumulation and an egg fuse.
B). tissue and an egg fuse.
C). genetic and an egg fuse.
D). sperm and an egg fuse.
The answer is:
D).