Final answer:
There are 81 possible microstates if there were 3 boxes and 4 balls.
Step-by-step explanation:
The question is asking how many microstates are possible if there were 3 boxes and 4 balls. To determine this, we can use the formula for the number of microstates, which is equal to the number of different ways the balls can be distributed among the boxes. In this case, each ball can be placed in any of the 3 boxes, so we have 3 choices for each of the 4 balls. Therefore, the total number of microstates is 3^4 = 81. So the correct answer is a. 81.