A coin (H: heads; T: tails) is flipped and a number cube (1, 2, 3, 4, 5, 6) is rolled. What is the sample space for this experiment?
is it
;
H1, H2, H3, H4, H5, H6

H, T, 1, 2, 3, 4, 5, 6

H1, H2, H3, H4, H5, H6, T1, T2, T3, T4, T5, T6

or

T1, T2, T3, T4, T5, T6


(and please provide explanation)