`{:(,"Column I (Gas) ",,"Column II"( "Ratio " gamma=C_(p) //C_(v))),((A),"Ammonia", (p),1.20),((B),"Carbon dioxide",(q),1.30),((C ),"Carbon monoxide ",(r),1.40),((D),"Helium ",(s),1.66):}`
(a) `A-s,B-r,C-q,D-p ` (b) `A-p,B-q,C-r,D-s` (c ) `A-s,B-q,C-r,D-p` (d) `A-r,B-s,C-q,D-p`

Explanation

To solve the problem, we need to match each gas in Column I with its corresponding gamma ratio in Column II. The gamma (γ) ratio is defined as the ratio of specific heats (Cp/Cv) for different types of gases.

### Step-by-Step Solution:

1. **Identify the Gases and Their Types:**
- **Ammonia (NH3)**: This is a tetratomic molecule (4 atoms).
- **Carbon Dioxide (CO2)**: This is a triatomic molecule (3 atoms).
- **Carbon Monoxide (CO)**: This is a diatomic molecule (2 atoms).
- **Helium (He)**: This is a monatomic gas (1 atom).

2. **Determine the Gamma Values for Each Gas:**
- **Ammonia (NH3)**: For tetratomic gases, the gamma (γ) value is approximately **1.20**.
- **Carbon Dioxide (CO2)**: For triatomic gases, the gamma (γ) value is approximately **1.30**.
- **Carbon Monoxide (CO)**: For diatomic gases, the gamma (γ) value is approximately **1.40**.
- **Helium (He)**: For monatomic gases, the gamma (γ) value is approximately **1.66**.

3. **Match Each Gas with Its Gamma Value:**
- **Ammonia (A)** → **1.20 (s)**
- **Carbon Dioxide (B)** → **1.30 (q)**
- **Carbon Monoxide (C)** → **1.40 (r)**
- **Helium (D)** → **1.66 (p)**

4. **Formulate the Correct Pairing:**
- A-s (Ammonia - 1.20)
- B-q (Carbon Dioxide - 1.30)
- C-r (Carbon Monoxide - 1.40)
- D-p (Helium - 1.66)

5. **Select the Correct Option:**
- The correct pairing from the options given is **(c) A-s, B-q, C-r, D-p**.

### Final Answer:
The correct answer is **(c) A-s, B-q, C-r, D-p**.