Which of the Following Sets of Constraints Results in an Unbounded

Multiple Choice

Which of the following sets of constraints results in an unbounded maximizing problem?

A) X + Y > 100 and X + Y < 50
B) X + Y > 15 and X - Y < 10
C) X + Y < 10 and X > 5
D) X < 10 and Y < 20
E) All of the above have a bounded maximum.