Convert 3.125 inches to millimeters.

To convert inches to millimeters, you multiply the number of inches by the conversion factor, which is 25.4 mm per inch.

For 3.125 inches, the calculation would be:

3.125 inches × 25.4 mm/inch = 79.375 mm.

Rounding this to two decimal places gives approximately 79.38 mm. This corresponds exactly to the answer choice you provided. Understanding the significance of the conversion factor and the precision of rounding can help ensure accuracy in similar questions regarding unit conversions.