To find the cost of 5 shirts, we first need to determine the cost of one shirt.
From the sale, we know that: 3 shirts cost $27.
To find the cost of one shirt, we can divide the total cost by the number of shirts: \[ \text{Cost per shirt} = \frac{27}{3} = 9 \text{ dollars per shirt} \]
Now that we know the cost of one shirt is $9, we can find the cost of 5 shirts: \[ \text{Cost of 5 shirts} = 5 \times 9 = 45 \text{ dollars} \]
So, the cost of 5 shirts at the same rate is $45.
The answer is C. $45.