Who was Sal Castro? How did Sal Castro's personal history inform his actions
on behalf of his students?

Salvador B. Castro (October 25, 1933 – April 15, 2013) was a Mexican-American educator and activist. He was most well known for his role in the 1968 East Los Angeles high school walkouts, a series of protests against unequal conditions in Los Angeles Unified School District (LAUSD) schools.

Explanation:

offline recommendation systems option b

because recommendation systems produce a list of two ways

1. through collaborative filtering

or

2. through content-based filtering