Three major causes of mass migration today are

abraham lincoln was the president of usa and he had asked the audience to make a pledge on equality.

his pledge was:

“it is my earnest desire to know the will of the providence.”

lincoln also had hatred for people who condoned and practiced slavery and so he pledged:

""and if i can learnt what it is i can do it"" this is another pledge by abraham to reassure the congregation on how to deal with the providence will.

explanation:

hope this !

offline recommendation systems option b

because recommendation systems produce a list of two ways

1. through collaborative filtering

or

2. through content-based filtering