If a + b > 0 and a * b < 0, which of the following must be true?
I. a > 0 or b > 0
II. a < 0 or b < 0
III. a and b have the same sign  Choose the correct choice from the following answers.
A) I only
B) II only
C) III only
D) I and II only
E) I, II, and III
I. True, for the sum to be greater than 0, at least one of a or b has to be positive   II. True, for the product to be less than 0, one of a or b has to be negative   III. Not true, by the previous two, one of a or b has to be positive and the other has to be negative   I and II only
<result>D</result>
If a + b > 0 and a * b < 0, which of the following must be true?
I. a > 0 or b > 0
II. a < 0 or b < 0
III. a and b have the same sign