Answer:
C. Concentration gradient
Answer:
Option-D
Explanation:
Parkinson's diseases are a neural disorder which affects the movement of the human body. The disease is caused by the low production or no production of dopamine by the neurons which thus interfere with the impulse transfer and thus movement.
In the given question, the patient with Parkinson's disease is provided with levodopa but no improvement is observed therefore the prescriber must change the drug regimen, for example, the levodopa should be given in combination with carbidopa. These medications enter the blood-brain barrier and get converted to the dopamine.
Thus, Option-D is the correct answer.
