Answer: a. 720
Explanation:
You have 6 different sticks to choose from for the first stick. Then there are 5 for the second (6 - 1 = 5), then 4 for the third (5 - 1 = 4), etc all the way to the last stick.
Mathematically, this can be shown with 6!. In other words, 6 factorial.
6 * 5 * 4 * 3 * 2 * 1 = 720
The answer to our question is:
a. 720