Answer: C) 4.75 represents the shipping charge
The expression that models the cost is 1.0725x+4.75
The 1.0725x represents the cost after the 7.25% tax has been added on. Then the 4.75 is added on as well which is the flat shipping fee. It is considered constant as it does not change and stays at 4.75; this is in contrast to the variable term 1.0725x which does change when x changes (ie when you buy more shirts and increase x, then 1.0725x gets larger)