The best thing one can do after discovering an error in the implementation plan is to develop an options to meet the milestone date.
An implementation plan refers to a plan that outlines the steps to take when trying to accomplish a shared goal, objective, preset goals etc.
Thus, the option of develop an options to meet the milestone date will help to ensure the meeting holds
Therefore, the Option A is correct.
Read more about implementation plan
brainly.com/question/24864915