Let a,b,c be distinct non- negative numbers . If the vectors `ahat(i) + ahat(j) + chat(k) , hat(i) + hat(k) " and " chat(i) + c hat(j) + bhat(k)` lie in a plane then c is

Options

A. The arithmetic mean of a and b
B. The geometric mean of a and b
C. The harmonic mean of a and b
D. Equal to zero

Answer

B