The type of sampling used in the given statement is simple random sampling.
Simple random sampling: This is the type of probability sampling. In this type of sampling each and every unit of the population has an equal chance of being included in the sample. There are various of methods of choosing the sample randomly such as lottery method, use of random number tables, use of computers to generate random numbers etc.
In the given example, a pollster uses a computer to generate the random numbers and interviews the voters corresponding to those random numbers. Therefore, the method used here is simple random sampling.
Option 'C' is correct.
Since we have given that
A pollster uses a computer to generate 500 random numbers, then interviews the voters corresponding to those numbers.
Since Random sampling includes putting all names into a bowl and draw certain names. .In this type of sampling, each and every elements has equal chance of occuring.
Cluster sampling includes dividing the population into groups specially geographically and these groups are called clusters and in which each element of selected group are used.
Stratified sampling divides into group known as strata but not geographically.
This type of sampling that is used is Stratified sampling.
Hence, Option 'C' is correct.