d
Now, Applying Kircheffis law in the loop
$A B C F A$ :-
$\left.\Rightarrow 30 v-4 i_1\right.-3\left(i+i_1\right)-2(i)=0$
$\Rightarrow 30=4 i+3 i+3 i_1+2 i$
$\Rightarrow 9 i+3 i_1=30$
$\Rightarrow \quad 3 i+i_1=10$
$\Rightarrow \quad i=\frac{10-i_1}{3}-(1)$