For a maximization problem, the optimal solution will be found at:

a$.$ the extreme point $($one of the corner points$)$ that is furthest from the graph origin $(0,0)$

b$.$ the central point of the feasible region to guarantee feasibility.

c$.$ the extreme point that is nearest to the origin of the graph $(0,0).$

d$.$ the corner point that satisfies the most important constraint.