How do you convert inches to millimeters?

To convert inches to millimeters accurately, one must use the conversion factor where 1 inch equals 25.4 millimeters. By multiplying the number of inches by 25.4, you effectively scale the measurement to the equivalent length in millimeters. This relationship is fundamental in measurement conversions and is widely used in fields such as engineering, manufacturing, and science where precise measurements are required.

This option provides the exact multiplication factor needed for this conversion, making it the correct approach in transforming measurements from inches to a smaller unit, millimeters. The other options either present incorrect factors or methods, which would lead to inaccurate conversions.