(1 point) let v be a vector space over a field k, and let uj, u2, u3, u4 be vectors in v. suppose u4 is a linear combination of {u} , u2, u3}. select the best of the following statements (i. e., select the statement that is true and gives the most information). a. we only know that span{uj, u2, u3 } c span{u1, u2, u3, u4}. b. span{u} , u2, u3 } = span{u} , u2, u3, u4} . c. span{uj, u2, u3 } = span{uj, u2, u3, u4 } only when u4 is a scalar multiple of one of {u}, u2, u3 }. d. there is no obvious relationship between span{u} , u2, u3 } and span{ui, u2, u3, u4 } . e. none of the above