So we know that the dice had 6 numbers which is 1 to 6, and we know that the odd number between 1 and 6 is 1,3,5. As a result, the probability of rolling an odd number on a fair die is 3/6 or 1/2, and we already know that probability of flipping a tail on a coin is 1/2, so I just take 1/2 times 1/2 to get 1/4 which is C. Hope it help!