When Gretchen starts being chased by a dog, her brain sends a signal to her muscles to run. Which neurons are at work? sensory neurons motor neurons voluntary neurons involuntary neurons

The type neurons that is working in Gretchen's condition is the motor neurons. Although sensory neuron is also used to convert the external stimulus, the muscle movement is due to the signal from the motor neurons. Motor neurons are responsible for the of muscle movement may it be voluntary or involuntary.