The answer is false your welcome
A is the correct answer, NOT c. You don't list elements of the domain each time they occur, you enter each element of the domain only once
An expression does not have an equal sign.
Since the value of a nickel is 5 cents and you want to find out the value of n nickels (which means if you had any number of nickels) the expression would be
.05n
I only know this because I remember the common fractions, and 1/3 is .3333 repeating.