The stratified random sample is .

Correct option is C

A stratified random sample is a variation of the simple random sampling technique, designed to ensure representative subgroup selection from a heterogeneous population.
Basic information about the topic: Stratified random sampling is a probability sampling method where a heterogeneous population is divided into homogeneous sub-groups (strata), followed by simple random sampling within each stratum.
Information Booster:
Explanation of the correct answer in pointers in detail
· Variation of Simple Random Sampling: Stratified random sampling is an advanced probability sampling technique that adapts simple random sampling by adding a preliminary grouping step to reduce sampling error.
· Formation of Strata: The target population is divided into mutually exclusive, homogeneous sub-groups called strata based on specific characteristics (e.g., gender, age, income, academic stream).
· Random Selection Within Strata: Once strata are formed, researchers draw a simple random sample independently from within each stratum, either proportionally or unproportionally.
· Enhanced Representativeness: This method guarantees that minority sub-groups or specific sub-populations are adequately represented in the final sample, improving overall population generalizability.
Additional Knowledge:
Explanation of the other options apart from the correct statements
· Simple Random Sample:
· Why it is not correct: A simple random sample gives every individual in the entire target population an equal and independent chance of selection without any prior grouping or stratification. Stratified sampling builds upon this method but is a modified variation rather than a plain simple random sample.
· Smaller Homogeneous Group:
· Why it is not correct: A smaller homogeneous group describes an individual stratum itself (the sub-group created during the process), not the entire sampling methodology or the final composite sample.
· Biased Sample:
· Why it is not correct: Stratified random sampling is an unbiased, scientific probability sampling method. A biased sample arises from non-probability methods (like convenience or purposive sampling) or systematic sampling errors, whereas stratified sampling actively eliminates representation bias across key variables.