To solve this question, we will evaluate each of the pairs provided in the list to determine which ones correctly describe a concept or method related to statistics or methodologies.

1. Central tendency - Mean: This is correct. Central tendency is a statistical measure that identifies a single value as representative of an entire distribution of data. The mean, also known as the average, is a commonly used measure of central tendency.
2. Regression curve - Hypothesis: This combination is incorrect. A regression curve is a tool in statistics used to understand the relationship between variables. It helps in making predictions and does not directly relate to a hypothesis, which is a proposed explanation for a phenomenon based on limited evidence as a starting point for further investigation.
3. Refinement of judgement - Delphi method: This is correct. The Delphi method is a structured communication technique used to achieve a converging opinion or decision by refining judgments through several rounds, allowing experts to refine their opinions based on anonymous feedback over multiple iterations.
4. Absolute zero point - Likert Scale: This combination is incorrect. Absolute zero point refers to the lowest point on a physical scale (like temperature in Kelvin). The Likert scale, however, is used for survey-based research and is a psychometric scale commonly involved in research that employs questionnaires. It does not involve any absolute zero point.
5. Descriptive statistics - Median: Although the statement is partly correct as the median is indeed a part of descriptive statistics, it is not paired with a unique key term within this context, unlike other options clearly addressing inappropriate pairings.

Considering the evaluation above, the pairs that correctly match are:

• A. Central tendency - Mean
• C. Refinement of judgement - Delphi method

Thus, the correct answer is A, C Only.