If a and b are each greater than x and y, which of the following must be true?
I. a + b < x + y
II. ab > xy
III.a + b > x + y	Choose the correct choice from the following options:
A) I only
B) II only
C) I and II
D) III only
E) I, II and III
I. a + b &gt; x + y. Since a and b are each greater than x and y, then the sum of a and b will also be greater than the sum of x and y.   II. ab &gt; xy. Not necessarily true, consider a = b = 0 and x = y = -1 --&gt; ab = 0 &lt; 1 = xy.   III. |a| + |b| &gt; |x| + |y|. Not necessarily true, consider a = b = 0 and x = y = -1 --&gt; |a| + |b| = 0 &lt; 2 = |x| + |y|.   Answer: III only.
<result>D</result>
If a and b are each greater than x and y, which of the following must be true?
I. a + b < x + y
II. ab > xy
III.a + b > x + y