PLEASE HELP ME ASAP (REPOST) What is meant by the term bystander effect?

A. People can find that a group may be too large to have any cohesiveness.
B. Individuals tend to take more responsibility for reporting crimes than do groups of people.
C. Individuals may have more difficulty describing a person who committed a crime.
D. People tend to have more fun when they are in groups instead of being alone.

AP_EX - SOCIOLOGY

The tea party movement is a. an official third party that challenges both democrats and republicans in national elections. b. an organized challenge to incumbents in the republican party by the most conservative wing of the republican party. c. an organized challenge to incumbents in the democratic party by the most liberal wing of the democratic party. d. an offspring of the green party that runs for state and local office in many midwestern states. e. the now defunct party that gave way to the republican party at the end of the “second party system.”