Those groups which activate the benzene ring are generally

Options

A. o-directing
B. p-directing
C. o-and m-directing
D. o-and p-directing.

Answer

To solve the question regarding which groups activate the benzene ring, we need to analyze the effects of different substituents on the electron density of the benzene ring. Here’s a step-by-step breakdown:

### Step 1: Understand the Concept of Activation and Deactivation
- **Activation** refers to the ability of a substituent to increase the electron density on the benzene ring, making it more reactive towards electrophiles.
- **Deactivation** refers to the ability of a substituent to decrease the electron density on the benzene ring, making it less reactive towards electrophiles.

**Hint:** Remember that activating groups increase electron density, while deactivating groups decrease it.

### Step 2: Identify Electron Donating and Electron Withdrawing Groups
- **Electron Donating Groups (EDGs)**: These groups donate electron density to the benzene ring, often through resonance. Examples include -OH, -OCH3, -NH2, and alkyl groups.
- **Electron Withdrawing Groups (EWGs)**: These groups withdraw electron density from the benzene ring, often through resonance or inductive effects. Examples include -NO2, -CN, -COOH, and halogens like -Cl.

**Hint:** Classify the groups based on whether they donate or withdraw electrons.

### Step 3: Analyze the Directing Effects of Substituents
- **Ortho and Para Directing Groups**: EDGs typically direct incoming electrophiles to the ortho and para positions relative to themselves because they increase electron density at these positions.
- **Meta Directing Groups**: EWGs direct incoming electrophiles to the meta position because they decrease electron density at the ortho and para positions.

**Hint:** Consider where the electron density increases or decreases when substituents are attached.

### Step 4: Conclusion on Activation
- Since the question asks about groups that activate the benzene ring, we focus on EDGs that are ortho and para directing.
- Therefore, the correct answer is that groups which activate the benzene ring are generally **ortho and para directing**.

**Hint:** Look for groups that increase electron density at the ortho and para positions.

### Final Answer
The groups which activate the benzene ring are generally **ortho and para directing** (Option D).