Physics how to calculate disintegration energy

1. The problem statement, all variables and given/known data (a) Calculate the disintegration energy when 232/92U decays by alpha emission into 228/90Th. Atomic masses of 232/92U and 228/90Th are 232.037156u and 228.028741u, respectively. (b) For the 232/92U decay in part (a), how much of the disintegration energy will be carried off by the alpha particle? Given: Mass of 4/2He = 4.002603u c^2 = 931.5MeV

2. Relevant equations E=mc^2
 

3. The attempt at a solution Well for part (a), first I found the difference in the starting masses and the end masses ie, 232.037156u - (228.028741u + 4.002603u) = 0.005812u I then put this into the equation and got 5.413878MeV. I thought this was right until I read part (b) and now I'm starting to think this might be how I'm meant to do that part, not part (a). Could anyone tell me if I'm even on the right track with this question or should I be using different equations?

Ithink the answer is d