Which of the following are examples of sexual reproduction?

A yeast offspring grows out of the body of its parent in a process called budding.
A pollen grain from one flower fertilizes another flower, resulting in the development of a seed.
A bacterium copies its DNA and divides into two daughter cells in a process called binary fission.
A frog releases sperm over eggs that were laid by another frog, and these cells fuse together.
A piece of a starfish is broken off and grows into a new starfish in a process called regeneration.