Labor unions and businesses in the heavy equipment industry have asked the u.s. congress to place a tax on imported equipment in order to make it more expensive. they hope that this will allow u.s. producers to be more competitive. the u.s. heavy equipment industry appears to be seeking a(n):

Protective tariff

Explanation: Protective tariffs are basically designed to protect the domestic producers from foreign competition. These tariffs raise the retail price of imported products making them expensive in comparison to domestic  products and thereby making domestic products more  competitive.

Thus, by placing a tax on imported equipment in order to make it more expensive, these industries hope that Protective tariff will allow u.s. producers to be more competitive.

I would pick
1.cleaning and maintaining equipment and tools
2. Feeding materials into machines,and removing materials from the machine
3. Designing and enforcing safety procedures to the environment.

Hope this helps