Which job might be held by someone in a mid-level caste? doctor housekeeper farmer priest

The correct option is farmer

Explanation:

Persons born in the highest caste known Brahmin are priests and educated elites,ultimately priest is a wrong option.

The second level of caste known as kshatriya is meant for warlords.

Vaishyas is the middle-level of caste system specifically  for workers such farmers and those whose livelihood depends on similar menial jobs

There are two more classes of caste system that are not relevant in this context

the tariff was created to protect industry in the northern part of the united states. industries in the north were being driven out of business by imported goods that were priced at a low rate. the goal was to protect these industries   by taxing the goods.

this isn't a question and if you're going to list things be kind and use commas.