Explanation:

Let's examine each statement:

- Statement 1: Quicklime (CaO) is indeed used in the process of preparing lime solutions for whitewashing because it reacts with water to form slaked lime.

- Statement 2: The solution of slaked lime, formed when CaO reacts with water, is used for whitewashing walls.

- Statement 3: CaO does react slowly with CO₂ in the air to form a thin layer of CaCO₃, giving a durable finish on walls.

- Statement 4: Calcium hydroxide (Ca(OH)₂), known as slaked lime, is indeed an inorganic compound.

- Option 1: 1 and 4 only – This is incorrect; both are true, but so are other statements.

- Option 2: 2 and 4 – This is partly correct but excludes other accurate statements.

- Option 3: 2 and 3 – These are correct but exclude other true assertions.

- Option 4: 1, 3, and 4 – This includes all correct statements.

Based on the above evaluation, the correct answer is:

Option 4: 1, 3, and 4

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