Answer:
The power these devices produce is quite low.
Step-by-step explanation:
The option selected above shows how energy devices powered by body sweat are not that good. This is because the power of these devices is very low, which results in low amounts of energy that are not powerful enough to be used efficiently and can reduce the use of non-renewable energies. The other options only have positive points about these devices, this being the only option that shows a problem.