This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous System, Subject name: Physiology
Motion of the endolymph in the semicircular canals when the head is held still will result in the perception of: 
Select and explain. 
A. Being upside-down, B. Moving in a straight line, C. Continued rotation, D. Being upright and stationary
C: Continued rotation
Answer: C: Continued rotation 
Explanation: Ans. C. Continued rotationa. Relative motion between the endolymph and the cupulae of the semicircular canals is due to the inertia of the endolymph, whether the body motion is starting or stopping.b. As the fluid continues to move when the head has stopped moving, the cupulae will be stimulated, producing the sensation of rotary motion.c. Moving in a straight line, without acceleration, will produce no fluid movement and no sensation.d. The sensation of static body position is accomplished by the maculae, which are sensitive to gravity but not endolymph motion.