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. Given these facts, where is a zygote formed by sperm swimming to an egg among the following options:
- colder and wetter
 - ocean water
 - graptolites
 - rapid expansion
 - a delta
 - an archegonium
 - barnacles
 - an organism's body


 

      an archegonium   