Answer:
C) seems to be the correct one
Each alpha particle emitted decreases the mass of the nucleus by 4 and decreases the atomic number by 2.
Also, each beta particle will increase the atomic number by 1.
So if C emits 5 alpha particles the atomic mass decreases by 20 and the atomic number decreases by 10. Then emission of 2 beta particles brings the atomic number up to minus 8.
So a total of 7 particles have been emitted and the number of alpha particles emitted exceeds the number of beta particles emitted.
