If a, b, c are three non-coplanar vectors, then (a + b + c).[(a + b) × (a + c)] is
A. 0
B. 2[abc]
C. -[abc]
D. [abc]
Answer:C
If a, b, c are three non-coplanar vectors, then (a + b + c).[(a + b) × (a + c)] is
A. 0 B. 2[abc] C. -[abc] D. [abc]