**Core Concept**
The estimation of a disease burden in a community involves quantifying the impact of a particular disease on the population. This is often achieved by calculating the Disability-Adjusted Life Years (DALYs) lost due to a specific disease or condition. DALYs take into account both the years of life lost due to premature mortality and the years lived with a disability.

**Why the Correct Answer is Right**
The correct answer is related to the estimation of disease burden using the Disability-Adjusted Life Years (DALYs) metric. The Global Burden of Disease (GBD) studies, which are widely recognized and cited, use DALYs to quantify the impact of various diseases on the global population. DALYs are calculated by combining years of life lost (YLLs) and years lived with disability (YLDs). This approach allows for a comprehensive understanding of the disease burden, enabling policymakers to make informed decisions regarding resource allocation and public health interventions.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specifically relate to the estimation of disease burden in a community. While it may be a relevant concept in epidemiology, it does not directly address the question.

**Option B:** This option is incorrect because it refers to a different epidemiological measure. The case-fatality ratio is a useful metric for comparing the severity of different diseases, but it does not provide a comprehensive estimate of disease burden.

**Option C:** This option is incorrect because it is a statistical measure used in hypothesis testing. While statistical significance is essential in epidemiological research, it does not directly relate to the estimation of disease burden.

**Option D:** This option is incorrect because it is a type of study design. While observational studies are crucial in epidemiology, they do not specifically relate to the estimation of disease burden.

**Clinical Pearl / High-Yield Fact**
When estimating disease burden, it is essential to consider both the years of life lost due to premature mortality and the years lived with a disability. This comprehensive approach, using DALYs, allows for a more accurate understanding of the impact of a disease on the population.

**Correct Answer: C. Disability-Adjusted Life Years (DALYs).**