Answer:
a. 6
Explanation:
"Mode" is the term for the most "popular" number of data. Let's say I have three buttons, two dimes, and one paperclip. The mode would be buttons because that's what I have the most of.
If you look at the given data:
# of 6s: Three
# of 4s: none
# of 3s: Two
# of 9s: One