Assertion : Oxygen has oxidation states of -2 in both `O_2 and O_3`.
Reason : Oxygen is assigned an oxidation state of - 2 in almost all its compounds.

Options

A. Assertion and reason both are correct statements and reason is correct explanation for assertion.
B. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
C. Assertion is correct statement but reason is wrong statement.
D. Assertion is wrong statement but reason is correct statement.

Answer

To solve the assertion and reason question, we will analyze both the assertion and the reason step by step.

### Step 1: Analyze the Assertion
The assertion states: "Oxygen has oxidation states of -2 in both O2 and O3."

- **O2 (Dioxygen)**: In molecular oxygen (O2), each oxygen atom is in its elemental form. The oxidation state of an element in its standard state is 0. Therefore, the oxidation state of oxygen in O2 is 0.

- **O3 (Ozone)**: In ozone (O3), the structure consists of three oxygen atoms. The oxidation states of the oxygen atoms in ozone are not all -2. In fact, the average oxidation state of the oxygen atoms in O3 is 0, as the oxidation states can be considered as +1, -1, and 0 for the three oxygen atoms.

Thus, the assertion that oxygen has an oxidation state of -2 in both O2 and O3 is **incorrect**.

### Step 2: Analyze the Reason
The reason states: "Oxygen is assigned an oxidation state of -2 in almost all its compounds."

- This statement is generally true. Oxygen typically has an oxidation state of -2 in most of its compounds, such as water (H2O) and oxides (e.g., CO2, SO2). However, there are exceptions, such as in peroxides (where it has an oxidation state of -1) and in compounds with fluorine (like OF2, where it has an oxidation state of +2).

Thus, the reason that oxygen is assigned an oxidation state of -2 in almost all its compounds is **correct**.

### Conclusion
- The assertion is **incorrect**.
- The reason is **correct**.

Therefore, the answer is:
**Assertion is the wrong statement but Reason is the correct statement.**

### Final Answer
**Option 4: Assertion is the wrong statement but Reason is the correct statement.**

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