What is the sample space when a coin is tossed twice?

Responses
A {HH, HT}{HH, HT}
B {HH, HT, TT, TH}{HH, HT, TT, TH}
C {HH, TT, TH}{HH, TT, TH}
D {H, T}

B {HH, HT, TT, TH}{HH, HT, TT, TH}