**Core Concept**
The assessment of a health programme involves evaluating its effectiveness in achieving desired outcomes. This can be done by expressing the benefit in terms of results achieved, which is a key aspect of programme evaluation.

**Why the Correct Answer is Right**
The correct answer is Outcome Evaluation. Outcome evaluation assesses the impact of a health programme on the target population by measuring the results achieved, such as changes in health status, behavior, or quality of life. This type of evaluation helps to determine whether the programme has achieved its intended goals and whether the benefits outweigh the costs.

* **Option A:** Process Evaluation is incorrect because it focuses on assessing the implementation of a health programme, including its structure, activities, and inputs, rather than evaluating the outcomes achieved.
* **Option B:** Impact Evaluation is incorrect because it assesses the long-term effects of a health programme, often using quasi-experimental or experimental designs, but it is not the primary method for expressing benefits in terms of results achieved.
* **Option C:** Efficiency Evaluation is incorrect because it focuses on assessing the cost-effectiveness and cost-benefit of a health programme, rather than evaluating the outcomes achieved.

**Clinical Pearl / High-Yield Fact**
When evaluating a health programme, it is essential to distinguish between process, outcome, and impact evaluations to ensure that the programme is achieving its intended goals and that the benefits outweigh the costs.

**Correct Answer: C. Outcome Evaluation**