Find the Minimum Value of the Objective Function and Where

Multiple Choice

Find the minimum value of the objective function and where it occurs, subject to the indicated constraints. ​
Objective function:
​
Z = 5x + 4y
​
Constraints:
​
X ≥ 0
Y ≥ 0
X + y ≤ 5​
​​ ​

A) Minimum at (5, 0) : 26
B) Minimum at (0, 5) : 21
C) Minimum at (0, 0) : 0
D) Minimum at (0, 5) : 25
E) Minimum at (5, 0) : 20