Multiple choice question, only one choice is right. Please provide brief justification as well, thank you.

(b) If you reject a joint null hypothesis using a Ftest in a regression with multiple regressors, then: i. A series of t-tests may or may not give you the same conclusion, ii. The regression is always signicant, iii. All of the hypotheses are always simultaneously rejected, iv. The Fstatistic must be negative