The correct option is
A zero vector
Let
→a=^i
→b=^j
→c=^k
By vector reciprocal
→a′=→b×→c[→a→b→c]
→a×→a′=→a×(→b×→c)[→a→b→c]
→a×→a′=^i×(^j×^k)[→a→b→c]
→a×→a′=0[→a→b→c]
→a×→a′=0
→b′=→c×→a[→a→b→c]
→b×→b′=→b×(→c×→a)[→a→b→c]
→b×→b′=^j×(^k×^i)[→a→b→c]
→b×→b′=0[→a→b→c]
→b×→b′=0
→c′=→a×→b[→a→b→c]
→c×→c′=→c×(→a×→b)[→a→b→c]
→c×→c′=^k×(^i×^j)[→a→b→c]
→c×→c′=0[→a→b→c]
→c×→c′=0
→a×→a′+→b×→b′+→c×→c′=0