During passage through the large intestine,a trophozoite will often secrete a case around itself,forming a cyst.Cysts contain four haploid nuclei.When cysts "hatch" within a new host,two trophozoites are released.Thus,which of the following must happen within the cyst,prior to hatching?
1)meiosis
2)nuclear division
3)S phase
4)binary fission
A)1 only
B)1 and 2
C)2 and 3
D)2 and 4
E)2, 3, and 4