**Core Concept**
Simple Random Sampling is a statistical technique used to gather data from a population by randomly selecting a subset of individuals or samples. This method aims to minimize bias and ensure that the sample is representative of the population.

**Why the Correct Answer is Right**
In Simple Random Sampling, every member of the population has an equal chance of being selected for the sample. This is achieved through the use of randomization techniques, such as random number generators or random selection from a hat. The goal is to create a sample that is representative of the population, allowing researchers to make inferences about the population based on the sample data. By using Simple Random Sampling, researchers can reduce the impact of sampling bias and increase the accuracy of their findings.

**Why Each Wrong Option is Incorrect**
**Option A:** Stratified Sampling is a different statistical technique that involves dividing the population into subgroups or strata and then randomly sampling from each subgroup. This method is used to ensure that the sample is representative of the population's subgroups.
**Option B:** Systematic Sampling involves selecting samples based on a fixed interval or pattern, which can lead to sampling bias if the interval is not randomly determined.
**Option C:** Convenience Sampling involves selecting samples based on ease of access or convenience, which can lead to biased samples and inaccurate results.

**Clinical Pearl / High-Yield Fact**
Simple Random Sampling is a fundamental technique in epidemiology and research studies, allowing researchers to make accurate inferences about a population based on a representative sample.

**Correct Answer: D. Simple Random Sampling is a statistical technique used to gather data from a population by randomly selecting a subset of individuals or samples.**