Three vectors `veca,vecb` and `vecc` satisfy the relation `veca.vecb=0` and `veca.vecc=0`. The vector `veca` is parallel to

Answer

A

Explanation

For triangle `ABC: vec(AB)+vec(BC)+vec(CA)=vec(0)`
Now `vec(AB)+vec(BC)+2vec(CA)`
`=vec(AB)+vec(BC)+vec(CA)+vec(CA)+vec(0)+vec(CA)=vec(CA)`