Final answer:
The number of outfit combinations that can be put together is 72.
Step-by-step explanation:
To find the number of outfit combinations, we need to multiply the number of choices for shirts, pants, and shoes together.
Given that we have 6 shirts, 3 pairs of pants, and 4 pairs of shoes, the number of combinations can be calculated as follows:
Number of combinations = 6 shirts * 3 pants * 4 shoes = 72
Therefore, the correct answer is 72, option A.