State the domain of the function shown below
select one:
a. (–∞, 0) incorrect
b. (–∞, ∞) incorrect
c. [0, ∞)
d. [0, –∞)

Answer asap and if you do you will get brainliest. catherine buys a gallon of ice cream from the store. after taking it home, she eats a fifth of a gallon of ice cream. her sister eats some of the ice cream as well. if two-thirds of the original amount of ice cream is left, then what fraction of a gallon of ice cream did her sister eat?