What did the montgomery bus boycott teach civil rights activists in montgomery and elsewhere?
one person could make a difference.
segregation laws could be changed.
nonviolent resistance could inspire a violent response.
nonviolent resistance could succeed in ending segregation.

Nonviolent resistance could succeed in ending segregation  is the right answer

Explanation:

A 13 month mass protest of bus boycott in the year 1955 with the arrest of Rosa Park in USA is known as the Montgomery Bus Boycott. In the leadership of Martin Luther, the boycott is an example of successful abolishing of segregation through nonviolent protest. This protest led the Supreme Court’s decision on un-constitutionalism of public buses.

It gained support outside the Montgomery. With the end of the boycott the segregated sitting in buses were removed by the laws of the Supreme Court.  

b. major john c. frémont led a rebellion called the bear flag revolt.

explanation:

during the bear flag revolt, from june to july 1846, a small group of american settlers in california rebelled against the mexican government and proclaimed california an independent republic. the republic was short-lived because soon after the bear flag was raised, the u.s. military began occupying california, which went on to join the union in 1850. the bear flag became the official state flag in 1911.