By components do you mean organs? If so...
1. Brain - gives demands ands orders to all of the body to function properly
2. Heart - pumps blood, and keeps the organism receiving the blood alive
3. Skin - protects the tissue from UV Rays that may be harmful
The answer is D, improves strength
C. ophthalmic medication
The most common form of medications for ear and eye problems are in drops. When the pharmacists dispense medications for the eyes or ears, they must double check the labels to prevent errors, specially because (the type of) antibiotics used for infections of the eyes and ears are similar.