Insert the Missing Code in the Following Code Fragment

Insert the missing code in the following code fragment. This fragment is intended to implement a method to increase the speed of the motor by one step if possible.
Public class Motor
{
Public static final STOPPED = 0;
Public static final SLOW = 1;
Public static final MEDIUM = 2;
Public static final FAST = 3;
Private int motorSpeed;
) . .
Public void increaseMotorSpeed()
{
If(motorSpeed < FAST)
{
________
}
}
}

A) motorSpeed ++;
B) motorSpeed = SLOW;
C) motorSpeed = MEDIUM;
D) motorSpeed = FAST;