The Objective Function for an Optimization Problem Is: Max 5x

The objective function for an optimization problem is: Max 5x - 3y, with constraints x ≥ 0, y ≥ 0 and y must be an integer. x and y are the only decisions variables. This is an example of a(n)

A) all-integer linear program.
B) mixed-integer linear program.
C) LP relaxation of the integer linear program.
D) binary integer linear program.