B. Sperm released by one sponge swim to other sponges
(Fertilization is the term used to state when a male gametes fuses with a female gamete)
Explanation:
An amoeba reproduces via the process known as binary fission.
After replicating its genetic material through mitotic division, the cell divides into two equal sized daughter cells.

OR
•Yeast is a unicellular organism. Yeast reproduces via the asexual process known as budding.
•Budding usually occurs when food is available in plenty.
•In budding, one or more outgrowths appear on one side, which increases in size.
•The nucleus divides through mitosis, one daughter nucleus passes into the bud and the other remains in the parent cell.
•The bud either separates off from the parent cell or new bud appears before its separation from the parent cell resulting in the formation of branched or unbranched chain of buds.