Assertion: It has been found that for hydrogenation reaction the catalytic activity increases from group5 to group-11 metals with maximum activity being shown by groups 7-9 elements of the periodic table. Reason: For 7-9 group elements adsorption rate is maximum.

Options

A. Both assertion and reason are correct and reason is correct explanation of assertion.
B. Both assertion and reason are correct and reason is not correct explanation of assertion.
C. Assertion is true & reason is false.
D. Both are incorrect

Explanation

To solve the question, we need to analyze the assertion and the reason provided and determine their correctness.

### Step 1: Analyze the Assertion
The assertion states that for hydrogenation reactions, the catalytic activity increases from group 5 to group 11 metals, with maximum activity shown by groups 7 to 9 elements of the periodic table.

- **Understanding Catalytic Activity**: Catalytic activity refers to the ability of a substance (catalyst) to increase the rate of a chemical reaction. In the context of hydrogenation, this involves the addition of hydrogen to a compound.
- **Periodic Trends**: In general, as we move from group 5 to group 11 in the periodic table, the metals tend to have varying catalytic properties due to differences in their electronic configurations, oxidation states, and the ability to adsorb reactants on their surface.

### Step 2: Analyze the Reason
The reason provided states that for groups 7 to 9 elements, the adsorption rate is maximum.

- **Adsorption**: Adsorption is the process by which atoms, ions, or molecules from a gas, liquid, or dissolved solid adhere to a surface. In catalysis, higher adsorption rates can lead to increased reaction rates.
- **Relation to Catalytic Activity**: If the adsorption rate is maximum for groups 7 to 9, it implies that these metals can effectively hold the reactants on their surface, facilitating the hydrogenation process.

### Step 3: Conclusion
Both the assertion and the reason are correct. The assertion accurately describes the trend in catalytic activity across the specified groups, and the reason correctly explains why these groups exhibit maximum activity due to their high adsorption rates.

### Final Answer
- **Assertion**: True
- **Reason**: True
- **Explanation**: The reason is a correct explanation of the assertion.