Smooth endoplasmic recticulum is well developed in the cells which synthesise

Options

A. steroids
B. proteins
C. carbohydrates
D. All of these

Explanation

### Step-by-Step Solution:

1. **Understanding the Endoplasmic Reticulum (ER)**:
- The endoplasmic reticulum is an organelle in eukaryotic cells and is classified into two types: rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER).
- RER is studded with ribosomes, giving it a rough appearance, while SER lacks ribosomes and appears smooth.

2. **Functions of Smooth Endoplasmic Reticulum**:
- The smooth endoplasmic reticulum is primarily involved in the synthesis of lipids, including phospholipids and cholesterol.
- It also plays a role in the metabolism of carbohydrates and the detoxification of drugs and poisons.

3. **Analyzing the Options**:
- **Option A: Steroids** - The SER is involved in the synthesis of steroid hormones, which are a type of lipid.
- **Option B: Proteins** - Proteins are synthesized in the rough endoplasmic reticulum, not the smooth.
- **Option C: Carbohydrates** - While SER can be involved in carbohydrate metabolism, it is not primarily known for synthesizing carbohydrates.
- **Option D: All of these** - This option suggests that SER synthesizes all mentioned compounds, which is incorrect since proteins are synthesized in RER.

4. **Conclusion**:
- The smooth endoplasmic reticulum is well developed in cells that synthesize steroids and lipids. Therefore, the correct answer is **Option A: Steroids**.