Oils remains as liquid in winters because

Options

A. They have higher melting point.
B. They contain unsaturated hydrocarbons
C. They have single carbon-carbon bonds.
D. Both (b) and (c)

Answer

To answer the question "Oils remain as liquid in winters because," we need to analyze the properties of oils and their molecular structure.

### Step-by-Step Solution:

1. **Understanding the Properties of Oils**:
- Oils are typically liquid at room temperature and remain liquid even in colder conditions, such as winter. This characteristic is essential for understanding why they do not solidify.

2. **Melting Point Consideration**:
- For a substance to remain liquid at lower temperatures, it must have a low melting point. Therefore, if oils are liquid in winter, it implies they have a lower melting point.

3. **Analyzing the Options**:
- **Option A**: "They have higher melting point."
- This is incorrect because a higher melting point would mean that the oils would solidify at lower temperatures.
- **Option B**: "They contain unsaturated hydrocarbon."
- This is correct. Unsaturated hydrocarbons have one or more double bonds between carbon atoms, which prevent the molecules from packing closely together, thus lowering the melting point.
- **Option C**: "They have single carbon-carbon bonds."
- This is incorrect. Oils typically contain double bonds (unsaturated), not just single bonds.
- **Option D**: "Both B and C."
- This is incorrect because while B is correct, C is not.

4. **Conclusion**:
- The correct answer is **Option B**: "They contain unsaturated hydrocarbon." This property allows oils to remain liquid at lower temperatures due to the presence of double bonds that create bends or kinks in the fatty acid chains, preventing tight packing.