Question

When a group of units representing all units of population is investigated..
(CH
(a)
Sample survey
(b)
Survey for all
(C)
Secondary survey
Census survey​

Answer 1

Answer:

C option is correct rather than other

Answer 2

Secondary survey is one which represents that all units of population is investigated.

Explanation:

• Secondary survey is one which all units of a population are tested instead of testing each and every person in a population.
• Secondary survey is the most effective way of survey which helps the people to identify the approximate value of population in a particular area.
• Secondary survey is a simple and effective process which will help us to evaluate the growth of the population in the future.

To know more:

1) Meaning..what is a survey ?

https://brainly.in/question/4703546.

2) What where the purpous of surveys?

https://brainly.in/question/3923762