If d + xy = d and x is not equal to 0, which of the following must be true?
Choose the correct answer.
A) x=0 B) x+y=0 C) x<y D) y=0 E) x=d
d + xy = d --&gt; xy=0. Since x is not equal to 0, thus y = 0.   Answer: y=0.
<result>D</result>
If d + xy = d and x is not equal to 0, which of the following must be true?