How deep is the San Juan River in Metro Manila?

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.

the answer would more than likely a.)falling crop prices  

hope the answer is right and ,either way have a nice day.