Answer:
The clincal manifestation that is most diagnostic for Tay-Sachs disease is c. Cherry red spot on the retina.
Step-by-step explanation:
The Tay Sachs is a degenerative disease that affects the nervous system and the syntoms have to do with movemnt lost, cognitive impediments, lost of eye sight and finally death.
The presence of different syntoms are caused of the disease, but the doctor would examine the eye and most likely would determine the so called cherry red spot on the retine, that would suggest strongly the diagnose for this disease.