Which of the following input-output relationships are functions? SELECT ALL THAT APPLY. A. Input: The side length of an equilateral triangle; Output: The triangle’s area

B. Input: The number of words in students’ essays; Output: The essay scores

C. Input: The time that an airplane has been in flight; Output: The airplane’s altitude

D. Input: The time since depositing money in a savings account; Output: The account balance

E. Input: The amount of time a student studies each day; Output: The amount of time the student sleeps each night