Which system of inequalities has no solution?
A. x+3y is greater than or equal to 0.5
x+3y is less than or equal to 2.5
B. x+3y is greater than or equal to 0.5
x+3y is greater than or equal to 2.5
C. x+3y is less than or equal to 0.5
x+3y is greater than or equal to 2.5