Answer:
3 0ver 8 (a)
because:
(h =heads)-(t=tails)
(hhh), (ttt), (hht), (hth), (thh), (htt), (tth), (tht)
the total number of options is 8 and 3 of them give you
1 head and 2 tails
so you take the 3 options and put it over 8 so 3/8 (A)
hope this helps