Respuesta :

The human activity that uses most of the water in United States is "a.Industry". The industries that consumed a lot of water includes manufacturing and mining steel, paper and chemical associated products. Water are used for cooling in factories, washing and rinsing in manufacturing process.
The human activity that uses the most water in the United States of America is industry. The correct option among all the options that are given in the question is the first option or option "a". A lot of industries like mining, steel, paper, chemical etc. use water in abundance. I hope the answer helps you.