In nuclear reaction, \({ }_{2}^{4} \mathrm{He}+{ }_{\mathrm{Z}} \mathrm{A} \rightarrow{\mathrm{z}}+2 \mathrm{Y}^{\mathrm{A}+3}+\mathrm{A}\) A denotes:
A. electron
B. positron
C. proton
D. neutron
Answer:D
In nuclear reaction, \({ }_{2}^{4} \mathrm{He}+{ }_{\mathrm{Z}} \mathrm{A} \rightarrow{\mathrm{z}}+2 \mathrm{Y}^{\mathrm{A}+3}+\mathrm{A}\) A denotes:
A. electron B. positron C. proton D. neutron