Pull factor related to immigration is best defined as
a something that causes people to leave their country.
b something that draws people to a new country.
c any problem immigrants have in a new country.
d any law that works to oppose immigration.

B something that draws people to a new country.

Explanation:

Through the American history, people have been attracted to moving to the US for a few distinct reasons. This incorporates religious opportunity, financial chances (In this particular case, employments), instructive chances (education), or the capacity to possess their very own lands. These elements all speak to various opportunities and capacities that people in the US have the chance to seek after.

c.) biotic: snails; abiotic: temperature climate

the answer is the government.