`{:("List - I","List - II"),("(Crystal System)","(Exmaple)"),("A) Orthorhombic","1) Graphite"),("B) Monoclinic","2) "MgSO_(4).7H_(2)O),("C) Triclinic","3) "FeSO_(4).7H_(2)O),("D) Hexagonal","4) "H_(3)BO_(3)):}`

Options

A. `{:(A,B,C,D),(2,3,4,1):}`
B. `{:(A,B,C,D),(2,3,1,4):}`
C. `{:(A,B,C,D),(1,2,3,4):}`
D. `{:(A,B,C,D),(1,2,4,3):}`

Answer

To solve the problem of matching crystal systems with their respective examples, we will analyze each crystal system and its corresponding example step by step.

### Step-by-Step Solution:

1. **Identify the Crystal Systems**:
- The crystal systems we have are:
- A) Orthorhombic
- B) Monoclinic
- C) Triclinic
- D) Hexagonal

2. **Identify the Examples**:
- The examples provided are:
- 1) Graphite
- 2) MgSO₄·7H₂O
- 3) FeSO₄·7H₂O
- 4) H₃BO₃

3. **Match Graphite**:
- Graphite is known to have a hexagonal crystal structure. Therefore, we match:
- D) Hexagonal → 1) Graphite

4. **Match MgSO₄·7H₂O**:
- Magnesium sulfate heptahydrate (MgSO₄·7H₂O) crystallizes in the orthorhombic system. Thus, we match:
- A) Orthorhombic → 2) MgSO₄·7H₂O

5. **Match FeSO₄·7H₂O**:
- Iron(II) sulfate heptahydrate (FeSO₄·7H₂O) has a monoclinic crystal structure. Hence, we match:
- B) Monoclinic → 3) FeSO₄·7H₂O

6. **Match H₃BO₃**:
- Boric acid (H₃BO₃) has a triclinic crystal structure. Therefore, we match:
- C) Triclinic → 4) H₃BO₃

7. **Final Matching**:
- Now we can summarize the matches:
- A) Orthorhombic → 2) MgSO₄·7H₂O
- B) Monoclinic → 3) FeSO₄·7H₂O
- C) Triclinic → 4) H₃BO₃
- D) Hexagonal → 1) Graphite

8. **Conclusion**:
- The final matches are:
- A → 2
- B → 3
- C → 4
- D → 1

### Final Answer:
The correct matching is:
- A) Orthorhombic → 2) MgSO₄·7H₂O
- B) Monoclinic → 3) FeSO₄·7H₂O
- C) Triclinic → 4) H₃BO₃
- D) Hexagonal → 1) Graphite

Thus, the answer is A2, B3, C4, D1.

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