Adownfall of the infant-industry argument is that a. most industries need protection when they are mature, not when they are first established. b. the amount of the tariff is unlikely to have much impact on the success of an infant industry. c. once a tariff is granted, political pressure will likely force withdrawal of the tariff before the industry matures. d. once established, a tariff is politically difficult to remove.

The correct response is Option D.  Once established, a tariff is politically difficult to remove.

Explanation:

Tariffs might seem like a good way to help support industries that are just beginning to develop and to support innovation and new economic diversification in the national context, but industries can become dependent on such tariffs and it may distort how competitive they are compared to other international brands that make the same products in the same industries. If the industry becomes important in terms of job creation and providing employment to workers it can become politically difficult to remove the tariffs as voting citizens may lose their jobs if their company takes a downturn.

  b.

there are isolated pockets of farming, generally around rivers and oases, which are used for irrigation.