Choice A is the correct answer. Test all vertices.

1. (0,0): $0$
2. (6,0): $5(6) + 3(0) = 30$
3. (4,4): $5(4) + 3(4) = 20 + 12 = 32$
4. (0,5): $5(0) + 3(5) = 15$
5. Maximum: 32

?�� Strategic Tip: The maximum isn't always at the axis intercepts.

Choice B is incorrect because 30 is less than 32. Choice C is incorrect because 15 is less than 32. Choice D is incorrect because 20 is less than 32.