First, let's calculate the total cost if the purchase is done in the local camera shop:
[tex]\begin{gathered} C=18\cdot9.95\cdot1.05 \\ C=188.06 \end{gathered}[/tex]Now, let's calculate the cost if the purchase is done in the mail-order company:
[tex]\begin{gathered} C=18\cdot9.75+15 \\ C=175.5+15 \\ C=190.5 \end{gathered}[/tex]The smaller cost is $188.06, therefore the correct option is the fourth one.