Q.
A. a=(a.i)i+(a.j)+(a.k)k
B. a=(axi)+(axj)+(axk)
C. a=j(a.i)+k(a.j)+i(a.k)
D. a=(axi)xi+(axj)xj+(axkxk)
E. None of the above
Correct choice: A
Explanation: