**Core Concept**
Randomization in clinical trials is a statistical technique used to minimize bias by allocating participants to treatment groups in a way that is free from systematic error. This is crucial in ensuring the internal validity of the study and allowing researchers to draw causal inferences about the effects of the intervention.

**Why the Correct Answer is Right**
Randomization helps reduce selection bias in allocation of treatment by ensuring that participants are allocated to groups in a way that is unrelated to their potential outcomes or characteristics. This is achieved through the use of random number generators or other statistical methods to assign participants to treatment groups. By doing so, randomization minimizes the risk of confounding variables influencing the results of the study. The use of randomization also helps to balance the distribution of known and unknown confounders between treatment groups, making it easier to compare the outcomes between groups.

**Why Each Wrong Option is Incorrect**
**Option A:** Facilitating double blinding is an important aspect of clinical trials, but it is not the primary purpose of randomization. While randomization can help to achieve double blinding, it is not the same thing as double blinding.

**Option B:** While randomization can help to increase the generalizability of study findings, it is not primarily used to ensure that study subjects are representative of the general population. This is more relevant to the concept of sampling.

**Option C:** Randomization does help to ensure that groups are comparable on baseline characteristics, but this is a secondary benefit rather than the primary purpose. The primary purpose of randomization is to reduce selection bias.

**Clinical Pearl / High-Yield Fact**
When designing a clinical trial, it's essential to consider the type of randomization used, such as simple randomization, stratified randomization, or block randomization, to ensure that the allocation of participants to treatment groups is fair and unbiased.

**✓ Correct Answer: D. Reduce selection bias in allocation of treatment**