When being observed increases evaluation concerns, occurs; when being lost in a crowd decreases evaluation concerns, occurs.
a. groupthink; deindividuation
b. deindividuation; groupthink
c. social facilitation; social loafing
d. social loafing; social facilitation

C.

Explanation:

Social Facilitation can be defined as the improvement in a task when being surrounded by other people. The idea of social facilitation was first developed in 1898 by Norma Triplett. Though the concept was later named by Floyd Allport in 1920 as 'social facilitation.

In this concept, psychologists observed that when a person is surrounded by others he/she tend to show improvement in the tasks. The improvement is also shown when the person is being evaluated and observed.

Social Loafing, on the other hand, can be defined as the concept in which people put less effort when in a group. In this concept, it is observed, that people are prone to put less effort when they are put in a group to achieve a common goal than while achieving an individual goal. There tendency to work decreases while working in a group in comparison with when they work alone. This happens because the evaluation decreases in a crowd.

So, the correct answer to the question is option C.

c hydrophobia is the answer

definition was not one of the four methods