After implementing the action plan, it is important to (2 points)

a) monitor progress and evaluate results
b) define the problem and generate solutions
c) evaluate results and develop an action plan
d) generate solutions and monitor progress

It's easy! due the other options are out of logic and not congruent with the first statement.

If the action plan is already implemented that means it's already into effect, the plan is the solution to a problem that has been identified; and if the plan was put into effect, it's been already developed (that's the solution) and off course there's no way to evaluate any results before the plan has even been developed.

Thereby the correct is (A.), if the plan is implemented, the next steps are: monitoring and evaluation.

Explanation:

answer; no longer than a reasonable period of time;