To increase the acceleration of the dog sled, you would want to reduce the total mass being moved. According to Newton's second law, \( F = ma \) (force equals mass times acceleration), if you decrease the mass while maintaining the same force applied (for example, by the dogs pulling), the acceleration will increase.
Among the provided options, the correct answer to increase the acceleration of the dog sled would be:
remove a dog from the sled.
This would decrease the total mass of the sled, resulting in greater acceleration for the same force exerted by the remaining dogs.