d
Since $A^{2}=A \Rightarrow A^{3}=A \quad \Rightarrow \quad A^{4}=A$
$\therefore \quad(\mathrm{I}+\mathrm{A})^{4}$
$\quad = {\,^4}{{\rm{C}}_0}{{\rm{I}}^4} + {\,^4}{{\rm{C}}_1}{\rm{A}} + {\,^4}{{\rm{C}}_2}{{\rm{A}}^2} + {\,^4}{{\rm{C}}_3}{{\rm{A}}^3} + {\,^4}{{\rm{C}}_4}{{\rm{A}}^4}$
$=\mathrm{I}+15 \mathrm{A}$