Answer:
a. atonia suddenly occurs in an awake, alert individual.
Step-by-step explanation:
Atonia is a medical condition that involves the loss of muscle strength/tone or temporal paralysis of the postural muscles of the body. Atonia is one of the major symptoms in rapid eye movement sleep (REM sleep), but have been found to occur in people having the sleep disorder called Cataplexy.
Cataplexy occurs while a person is conscious and wide awake. It involves muscle atonia whereby the individual loses control of the voluntary muscles. A feeling of strong emotion as been tipped as the common factor that triggers this condition. Depending on how severe the attack, cataplexy is characterized by partial or full body collapse, drooping eyelid, speech difficulty, jaw dropping, head dropping etc. All these happen within duration of few minutes while the person remains conscious.