Given `a+b+c+d=0`. Which of the following statements(s) is (are) correct?

Given a + b + c + d = 0, which of the following statements are correct: 'a, b, c, and d must each be a null vector,

Given a +b+c+d=0 which of the following statement is incorrect

If rate constant k for a hypothetical reaction A rarr B is 0.75 s ^(-1) Which of the following statements (s) is (are) correct if [A]_(0) is the initial concentration?