Describe a ''push'' factor in migration

The factor forcing or convincing people to migrate (move)

Explanation: Push as in pushing away, that is one way to think of it. It is like something motivating someone to do something.

d) a constitutional amendment

the right answer is the third one: turnpikes went short distances to connect markets. turnpikes, also known as toll roads, were very important for trade and transportation (of people, goods and products) in the 19th century, coinciding with the expansion towards the west. they contributed significantly to the economic development of the united states.