An experiment is performed to determine the Young modulus of a metal wire. A student measures the tension (force) applied to the wire, its original length, its extension, and its diameter.

The percentage uncertainties in these measurements are:

• Tension: 3.0%
• Original length: 1.5%
• Extension: 5.5%
• Diameter: 2.5%

Which measurement contributes the largest percentage uncertainty to the calculated value of the Young modulus?