A particle is moving with initial velocity `bar(u)=hati-hatj+hatk`. What should be its acceleration so that it can remain moving in the same straight line?
A. `vec(a)=2hati-2hatj+2hatk`
B. `vec(a)=-2hati+2hatj+2hatk`
C. `vec(a)=3hati+3hatj+3hatk`
D. `vec(a)=1hati-1hatj`