Let a, b, c be three unit vectors such that \(\rm \vec{a}+\vec{b}+\vec{c}=0\). If \(\rm \lambda=\vec{a} . \vec{b}+\vec{b}. \vec{c}+\vec{c} . \vec{a}\) and \(\rm \vec{d}=\vec{a} \times \vec{b}+\vec{b} \times \vec{c}+\vec{c} \times \vec{a}\), then the ordered pair ( λ, \(\rm \vec{d}\)) is equal to:
1
(3/2, 3a × c)
2
(-3/2, 3c × b)
3
(-3/2, 3a × b)
4
(3/2, 3b × c)