Final answer:
The fee for signing up the day of the activity is 1.20x, which means individuals get charged 20% more. Hence the correct answer is option A
Step-by-step explanation:
The expression that represents the fee for signing up the day of the activity is 1.20x. This means that individuals signing up the day of the activity get charged 20% more than those who sign up before the day of the activity.
Hence the correct answer is option A