To find out how many free throws Tyler attempted per minute, you can divide the total number of free throws by the total number of minutes.
So, the calculation would be:
\[ \text{Free throws per minute} = \frac{\text{Total free throws}}{\text{Total minutes}} = \frac{240}{60} = 4 \]
Therefore, Tyler attempted 4 free throws per minute. The correct answer is 4.