What was the name for people who decided not to settle in one place but instead traveled along rail lines during the depression?

I believe the answer is: Hoboes

Hoboes is the collection of people who lost their home due to the massive unemployment which exist during the great depression. Since they can afford to rent a place, they are forced travel along rail lines and make small shelter from leftover metals as a protection from the rain.

offline recommendation systems option b

because recommendation systems produce a list of two ways

1. through collaborative filtering

or

2. through content-based filtering