Find the Maximum Value of the Objective Function and Where

Multiple Choice

Find the maximum value of the objective function and where it occurs,subject to the constraints: ​
Objective function:
​
Z = 7x + y
​
Constraints:
​
X ≥ 0
Y ≥ 0
3x + y ≤ 15
4x + 3y ≤ 30
​

A) Maximum at (0,0) : 0
B) Maximum at (5,0) : 35
C) Maximum at (0,6) : 46
D) Maximum at (6,3) : 45
E) Maximum at (3,0) : 21