Using the smart goal-writing criteria, what refers to being able to complete a goal?

In SMART goal-writing criteria, the one that refers to being able to complete a goal is: Attainable
In determining a goal, we need to make sore that the Goal is possible based on our current ability, otherwise we just make ourselves and other people that we lead to a massive failure that could destroy our Morale as a team

Idon't get it either

Your answer is d.all of the above! hope this ! : )