You are presented with the quiz "Where is a zygote formed by sperm swimming to an egg?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "fertilization occurs when sperm swim to an egg inside an archegonium" and "when a sperm cell fertilizes an egg cell, a fertilized egg or zygote is formed". 

So, what's the best answer to the question?


 

      an archegonium     