`CaCl_(2)+H_(2)SO_(4)underset(-HCl)overset((p))rarrCaSO_(4).2H_(2)Ooverset((q))rarr(r)overset(gt383K)rarr(s)`
Which of the following option describes, the products, reactants and the reaction conditions.

Options

A. a. `{:("(p)","(q)","(r)","(s)"),("Crystallisation","Heat at 393 K",2CaSO_(4).H_(2)O,CaSO_(4)):}`
B. b. `{:("(p)","(q)","(r)","(s)"),("Crystallisation","Heat at 393 K",2CaSO_(4).H_(2)O,CaSO_(4)),(,"at high pressure",,):}`
C. c. `{:("(p)","(q)","(r)","(s)"),("Higher temperature","Cool",CaSO_(4).H_(2)O,CaSO_(4)):}`
D. d. `{:("(p)","(q)","(r)","(s)"),("Higher pressure","Heat at 393 K",CaSO_(4),CaSO_(3)):}`

Explanation

To solve the given question, we need to analyze the chemical reaction step by step and identify the products, reactants, and reaction conditions.

### Step-by-Step Solution:

1. **Identify the Reactants**:
The reactants in the reaction are Calcium Chloride (CaCl₂) and Sulfuric Acid (H₂SO₄).

**Hint**: Look for the substances that are present before the reaction occurs.

2. **Write the Reaction**:
The reaction can be written as:
\[ \text{CaCl}_2 + \text{H}_2\text{SO}_4 \rightarrow \text{CaSO}_4 + 2\text{HCl} \]
This indicates that Calcium Chloride reacts with Sulfuric Acid to produce Calcium Sulfate and Hydrochloric Acid.

**Hint**: Identify the products formed from the reactants.

3. **Identify the Intermediate Product**:
The Calcium Sulfate (CaSO₄) formed can further undergo crystallization in the presence of water (H₂O), leading to the formation of hydrated Calcium Sulfate, specifically Calcium Sulfate Dihydrate (CaSO₄·2H₂O).

**Hint**: Look for any additional products that may form after the initial reaction.

4. **Temperature Conditions**:
The reaction conditions indicate that the process occurs at a temperature greater than 383 K. The intermediate product (CaSO₄·2H₂O) is formed at a specific temperature, which is mentioned as 393 K.

**Hint**: Pay attention to the temperature ranges provided in the question.

5. **Identify the Final Products**:
The final products after the reaction and crystallization are Calcium Sulfate Dihydrate (CaSO₄·2H₂O) and the remaining Calcium Sulfate (CaSO₄).

**Hint**: Determine what the final state of the reaction is after all processes are complete.

6. **Summarize the Findings**:
- **Reactants**: CaCl₂ and H₂SO₄
- **Intermediate Product**: CaSO₄·2H₂O
- **Final Product**: CaSO₄
- **Reaction Conditions**: Temperature > 383 K, specific crystallization at 393 K

### Conclusion:
Based on the analysis, we can summarize the options:
- **P**: Crystallization (the process occurring)
- **Q**: Temperature (393 K)
- **R**: CaSO₄·2H₂O (the intermediate product)
- **S**: CaSO₄ (the final product)

The correct option that describes the products, reactants, and reaction conditions is **Option A**.