Final answer:
When checking brake stroke on a tractor, the stroke should be measured with the engine off and reservoir pressure of 85 - 100 psi. The service brakes should be fully applied to accurately measure the stroke.
Step-by-step explanation:
The correct answer to the question is d) 85 - 100 psi.
When checking brake stroke on a tractor, the stroke should be measured with the engine off and reservoir pressure of 85 - 100 psi. The service brakes should be fully applied to accurately measure the stroke. This measurement ensures that the brakes are properly adjusted and functioning correctly.