Consider the following statements regarding the origin of polyploidy and choose the correct answer:
1. The egg may be fertilized by more than one sperm
2. There may be a failure of mitosis
3. Triploids may arise as a result of fertilization of unreduced gametes
4. An autotetraploid may arise either by the doubling of chromosomes or fertilization between two different gametes

A. Only 1 is true

B. Only 2 and 3 are true

C. Only 1, 2 and 3 are true

D. 1, 2, 3 and 4 are true

Answer: Option D