Answer:
Option a
Stratified random sample
Explanation:
(a) In stratified random sampling, a division of the population occurs in such a way that a population is stratified in different small groups or strata with common traits and same proportion both in population and sample. this type of sample so formed is known as stratified random sample.
(b) Simple random Sample:
This sample is formed by the random and unbiased selection of individual that represents the population.
(c) Population:
The entire set of individuals with certain specific characteristics represents a population whereas a sample is drawn out of the population and can be referred to as the subset of the population.
(d) Cluster Sample:
In this, separate sample groups are formed known as clusters, here sampling of random clusters take place.
