**Core Concept:** Understanding the context of a public health issue in a disadvantaged population and the importance of education and socioeconomic status in health outcomes.

**Why the Correct Answer is Right:** In this scenario, the best solution lies in implementing a sustainable, easily understood method for educating the mothers about preventing and managing diarrhoeal cases in children. This method should be cost-effective, easily accessible, and culturally appropriate. The use of pictorial or visual aids, such as posters, pamphlets or videos, can be helpful in reaching a large number of people and improving understanding, especially among the illiterate population.

**Why Each Wrong Option is Incorrect:**

A. **Incorrect because:** Intervention via healthcare professionals alone is not sustainable and may not reach all the mothers, especially those residing in remote areas or during emergencies.

B. **Incorrect because:** While addressing the cause (socioeconomic status) is important, it is beyond the scope of this solution. The focus should be on providing the best possible method to manage diarrhoeal cases in the current context.

C. **Incorrect because:** While community-based interventions are essential, relying solely on community health workers may not ensure proper education for all mothers. Using a combination of healthcare professionals and community-based interventions is optimal.

D. **Incorrect because:** Although addressing the issue of education is important, focusing solely on improving socioeconomic status would not guarantee better understanding of diarrhoeal management immediately. Combining interventions is the best approach.

**Clinical Pearl:** Educating healthcare professionals and involving community health workers can achieve a balance between reaching a large number of individuals, improving understanding, and addressing the underlying socioeconomic factors. This approach promotes a sustainable and effective method for preventing and managing diarrhoeal cases in children living in disadvantaged areas.

**Correct Answer:** D. Utilizing a combination of healthcare professionals and community health workers can provide the best solution. By involving healthcare professionals, children can receive proper education and management of diarrhoeal cases, while involving community health workers ensures that the message reaches a larger number of mothers, especially those residing in remote areas. This combined approach addresses the issue of illiteracy among mothers and the socioeconomic status of the community.