A carpenter had 28 nails from previous job and needs to buy more. A store has 7 boxes of nails and each box contains 100 nails. The carpenter needs to buy at least 3 boxes. The number of nails the carpenter will have after purchasing n boxes is represented by a function.
f (n) = 100n + 28
What is the practical domain of the function?
A) all integers from 3 to 7, inclusive
B) {328, 428, 528, 628, 728}
C) all real numbers from 3 to 7,
inclusive
D) all real numbers