What Combination of X and Y Will Provide a Minimum

Multiple Choice

What combination of x and y will provide a minimum for this problem?
Maximize Z = $3x + $15y
Subject to:
2x + 4y ? 12
5x + 2y ? 10

A) x = 0, y = 0
B) x = 0, y = 3
C) x = 0, y = 5
D) x = 1, y = 2.5
E) x = 6, y = 0