Question

how might wearable energy harvesters help people in the future?
they will make electronic medical devices unnecessary.
they will help engineers produce medical devices quickly.
they will charge important medical devices as people move.
they will allow medical devices to use smart watches for power.

Explanation:

Wearable energy harvesters can convert human - motion energy into electrical energy. This energy can be used to charge important medical devices as people move. They don't make medical devices unnecessary, nor do they directly help in quick production of medical devices, and they don't use smart - watches for power for medical devices.

Answer:

C. They will charge important medical devices as people move.