Which among the following in an example of tertiary acid amide ?

Options

A.
B.
C.
D.

Explanation

To determine which among the given options is an example of a tertiary acid amide, we need to understand the definitions and structures of primary, secondary, and tertiary acid amides.

### Step-by-Step Solution:

1. **Understand Acid Amides**:
- An acid amide is a functional group characterized by the presence of a carbonyl group (C=O) directly attached to a nitrogen atom (N). The general structure is R-CO-NH2 (for primary), R-CO-NHR' (for secondary), and R-CO-NR'R'' (for tertiary).

2. **Identify Primary Acid Amide**:
- In a primary acid amide, the nitrogen atom is bonded to one carbonyl group and two hydrogen atoms (NH2). This means it has the structure R-CO-NH2.

3. **Identify Secondary Acid Amide**:
- In a secondary acid amide, the nitrogen is bonded to one carbonyl group and one hydrogen atom, along with one alkyl group (R). The structure is R-CO-NHR'.

4. **Identify Tertiary Acid Amide**:
- A tertiary acid amide has the nitrogen atom bonded to one carbonyl group and two alkyl groups (R and R'). This means it has the structure R-CO-NR'R''.

5. **Analyze the Given Structures**:
- Examine each of the provided structures to identify which one fits the definition of a tertiary acid amide:
- **Option A**: Contains one hydrogen atom attached to nitrogen, indicating it’s a secondary acid amide.
- **Option B**: The nitrogen is bonded to three carbon atoms, indicating it is a tertiary acid amide.
- **Option C**: Contains one hydrogen atom attached to nitrogen, indicating it’s a secondary acid amide.
- **Option D**: Contains two hydrogen atoms attached to nitrogen, indicating it’s a primary acid amide.

6. **Conclusion**:
- Based on the analysis, **Option B** is the correct answer as it represents a tertiary acid amide.