What is required for sexual reproduction to occur?

Question

an individual that produces sperm and an individual that produces eggs
an individual that produces sperm and an individual that produces spores
an individual that produces buds and an individual that produces spores
an individual that produces buds and an individual that produces eggs

Answer 1

For sexual reproduction to occur, the requirement is:

an individual that produces sperm and an individual that produces eggs.

This allows for the fusion of male and female gametes (sperm and egg) to create a new organism.