AVG Free (Anti-Virus Only Product) 9.0

I know the answer to this question, but I have been asked to ask everyone how good would a manager be of a Medium Sized Business with 1 Server and 5- 10 Workstations have only AVG 9.0 Free Anti Virus. This business might I add is also on a cable modem in a 10K Population and does 500k to 1 Mil. in transactions. Is this enough protection?