Answer
m is the input with months as units
B is the output with number students as units
This is a function
Work Step by Step
We know that m is the input because it is inside the parentheses. B is the output because it is the "coefficient" of the parentheses. The units of months and students are both given in the problem. This is a function because there can only be one quantity of students that have birthdays for each month.
