Research supports that appears to be an effective ergogenic aid.
a. ginseng
b. ciwujia
c. eleutherococcus senticosus
d. caffeine

D. Caffeine

Explanation:

Ergogenic aids can be termed as nutritional aids, that is mostly used by the Athletes as recovery aid, or potential source of energy which helps to boost or enhance the glycogen level in the body, and helps delay fatigue.

A good example is Caffeine, in which studies have shown that, it helps to enhance mental activities, during most commonly on concentration, alertness, attention etc. It helps to maintain fitness when exhausting and repetitive tasks are involved.

[content deleted] - user123802726recklesschicken

if you are on the computer you can not take a picture but you can upload one but i am not sure about phones but i'm pretty sure it's the but to upload one just click the paper clip looking thing/ link thingy thing and upload a pic