## Core Concept
The question pertains to the process of obtaining a functional impression for a removable partial denture (RPD). A functional impression, also known as a mucostatic or selective-pressure impression, aims to capture the details of the oral mucosa in a functional state, ensuring optimal fit and comfort of the RPD. This concept is crucial in prosthodontics for achieving successful outcomes with RPDs.

## Why the Correct Answer is Right
The correct answer, **C. Border molding and selective-pressure technique**, is appropriate because it accurately describes a method used for obtaining a functional impression. Border molding helps in achieving an accurate peripheral seal by capturing the details of the denture-bearing area's borders. The selective-pressure technique allows for the impression material to be displaced in areas where pressure is applied, simulating the functional state of the mucosa under the denture. This method helps in distributing the forces exerted by the denture more evenly, reducing the risk of tissue irritation.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is incorrect because it does not specify a recognized technique for obtaining a functional impression for RPDs.
- **Option B:** While mucostatic impressions aim to capture the mucosa in its resting state without compression, this option does not accurately describe the method specifically tailored for functional impressions.
- **Option D:** This option is incorrect because it does not accurately represent a standard technique for functional impression taking in the context of RPD fabrication.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the **selective-pressure technique** allows for customized pressure application, which can be adjusted based on the specific needs of the patient and the design of the RPD. This technique is particularly useful in areas where a high degree of tissue support and stability are required. Understanding the indications and proper execution of this technique can significantly impact the success of the RPD.

## Correct Answer Line
**Correct Answer: C. Border molding and selective-pressure technique**