On starting your vehicle in motion from a stop. As you apply power to the drive wheels, they start to spin. What should you do?

A Take your foot off the accelerator.

explanation

Speed up very gradually when traction is poor, as in rain or snow. If you use too much power, the drive wheels may spin. You could lose control. If the drive wheels begin to spin, take your foot off the accelerator. [California Commercial Driver Handbook]