Select the correct answer. Which of these is an example of selective breeding?

A.
A scientist places bacteria in a Petri dish treated with antibiotics and observes what happens to the population over time.
B.
A farmer plants tomato seeds that have been genetically modified to be pest resistant in his garden.
C.
A farmer only allows trees that produce tart apples to reproduce until he has a population that only produces tart apples.
D.
A scientist uses the genetic material from a unicellular organism to create an exact copy of that organism.