Answer:
A. {u1,u2,u3,u4} is a linearly independent set of vectors unless one of {u1,u2,u3} is the zero vector.
Step-by-step explanation:
Given that u4 is not a linear combination of {u1,u2,u3}
This means there is no possibility to write u4 = au1+bu2+cu3 for three scalars a,b,and c.
This gives that
This implies that these four vectors are not linearly dependent but linearly independent.
Hence option a is right.
A. {u1,u2,u3,u4} is a linearly independent set of vectors unless one of {u1,u2,u3} is the zero vector.