Which of the following are antibacterials ?

Options

A. Penicillin
B. Sulphapyridine
C. Ofloxacin
D. All

Answer

To determine which of the given options are antibacterials, we will analyze each option step by step.

### Step 1: Understand what antibacterials are
Antibacterials, also known as antibiotics, are substances that either kill bacteria or inhibit their growth. They are used to treat bacterial infections.

**Hint:** Remember that antibacterials can be classified into two categories: bacteriostatic (inhibit growth) and bactericidal (kill bacteria).

### Step 2: Analyze the options
We have the following options to evaluate:
1. Penicillin
2. Sulfur
3. Pyridine
4. Ofloxacin
5. All

### Step 3: Evaluate each option
- **Penicillin:** This is a well-known antibiotic that is effective against many bacterial infections. It is classified as a bactericidal antibacterial.

- **Sulfur:** While sulfur compounds can have antibacterial properties, they are not typically classified as antibiotics in the same way as penicillin or ofloxacin. Therefore, it is not considered a primary antibacterial.

- **Pyridine:** Pyridine itself is not an antibacterial agent. It is a heterocyclic aromatic organic compound and does not have antibacterial properties.

- **Ofloxacin:** This is a fluoroquinolone antibiotic that is effective against a variety of bacterial infections. It is classified as a bactericidal antibacterial.

### Step 4: Conclusion
From the analysis:
- Penicillin is an antibacterial.
- Sulfur is not primarily classified as an antibacterial.
- Pyridine is not an antibacterial.
- Ofloxacin is an antibacterial.

Thus, the only options that are antibacterials are Penicillin and Ofloxacin. Therefore, the correct answer is **not all**; the correct option is **Penicillin and Ofloxacin**.

**Final Answer:** Penicillin and Ofloxacin are antibacterials.