The radius vector and linear momentum are respectively given by vectors $2 \hat{i}+\hat{j}+\hat{k}$ and $2 \hat{i}-3 \hat{j}+\hat{k}$. Then the angular momentum is:
(a) $2 i-4 \hat{k}$
(b) $4 \hat{i}-8 \hat{k}$
(c) $2 \hat{i}-4 \hat{j}+2 k$
(d) $4 i-8 j$