List the pull factors that may have contributed to people's choice to immigrate to the united states

Question asked:List the pull factors that may have contributed to people's choice to immigrate to the united states

My answer is:The positive aspects of some countries serve to attract more immigrants than others. Below are three examples of pull factors that draw migrants to receiving countries such as America. Higher standards of living/Higher wages: Economic incentives provide both the biggest push and pull factors for potential migrants.

c it says nothing about connecting those 2 seas.

d is the best answer for this question.