The total cost for an air conditioning consists of the cost of an air conditioner and the cost of installation. A fixed sales tax of \(10\%\) is charged on both the cost of the air conditioner and installation. If the cost of the air conditioner, excluding sales tax, was \(\$600,\) what was the total amount of the air conditioner and installation, including sales tax?

1) The sales tax on installation cost was \(\$6\)

2) The total sales tax was \(\$66\)

OA D