Yep :) You're right!
The total probability of anything is always 100%, obviously.
If there are 4 choices, and you're equally likely to select either one, you can do 100% / 4 choices = 25%.
One of them have to be correct, so 1 of the 4 are bound to be right. 1/4 is also the same as 25%, hence you're correct! :)