To solve the question, we need to identify what 'L', 'M', and 'N' represent in the context of nutrients and determine which food sources are rich in these nutrients. Let's break it down step by step.
### Step-by-Step Solution:
1. **Understanding Nutrients**:
- The passage states that food contains substances called nutrients, which provide energy for survival and growth.
- Nutrients are categorized into carbohydrates, fats, proteins, and also include 'L', 'M', and 'N'.
2. **Identifying 'L', 'M', and 'N'**:
- From the context, we can infer that 'L', 'M', and 'N' likely refer to specific types of nutrients.
- Based on common nutritional knowledge, we can hypothesize that 'L' could be fats, 'M' could be proteins, and 'N' could be vitamins or minerals.
3. **Analyzing Food Sources**:
- We need to determine which food sources are rich in carbohydrates, fats, proteins, and possibly vitamins or minerals.
- Common food sources include:
- **Cereals and Oats**: High in carbohydrates and some proteins, low in fats.
- **Fruits and Vegetables**: Contain carbohydrates, vitamins, minerals, and some fiber (roughage).
- **Milk and Butter**: High in fats and proteins.
- **Eggs and Meat**: Very high in proteins.
4. **Finding the Richest Source**:
- The question asks for the food source that is rich in 'L', 'M', and 'N'.
- From our analysis, fruits and vegetables provide a good balance of carbohydrates, vitamins, and minerals, making them a rich source of nutrients.
5. **Conclusion**:
- Therefore, the food source that is rich in 'L', 'M', and 'N' is **fruits and vegetables**.
### Final Answer:
Fruits and vegetables are rich in 'L', 'M', and 'N'.
