- AD, because 20 ÷ 4 is not a whole number
- BB, because is too large
- CC, because 5 − 9 is not a whole number
- DNone — all four answers are whole numbers
Step-by-Step Solution
A: , B: , D: are whole numbers. C: is less than 0, so it is not a whole number. Whole numbers are closed under addition and multiplication, but not under subtraction.
Answer: C) C, because 5 − 9 is not a whole number