Answer:
option (A)
Step-by-step explanation:
Proton is represented by 1 H 1
neutrons is represented by 0 n 1
Two protons + 2 neutrons = 2 (1 H 1) + 2 (0 n 1)
The atomic number is reduced by 2 and the mass number is reduced by 4.
An alpha particle has mass number 4 and atomic number 2. So, it emits alpha particle.