Every twenty-fifth person who subscribed to a weekly news magazine was contacted by market researchers to complete a survey of opinions regarding the magazine's contents. The researchers were applying the technique known as

a. naturalistic observation.

b. the double-blind procedure.

c. random sampling.

d. replication.

Random sampling

Explanation:

Random sampling is a way to select the sample from a population randomly for making inferences about the population. The exit poll is the example of random sampling which makes the inferences about the election. It is also called probability sampling.

There are different type of random sampling such as:

Simple random sampling Stratified random sampling Cluster sampling

Thus in the above statement, The researcher used random sampling to collect the data about magazine contents. This technique is also called random sampling or probability sampling.