Correct option is D. none of these
As \(\vec a+\vec b\) is collinear with \(\vec c\).
As \(\vec b+\vec c\) is collinear with \(\vec a\).
Adding \(\vec c\) both sides of the equation (i)
Adding \(\vec a\) both sides of the equation (iii),
Equating the RHS of equation (iii)& (iv), being their LHS equal,
As, a is not collinear with c,