How many stars are both Tyres and Pen?

Logic: To determine the number that represents the stars that are both tyres and pens, Identify the number present in the region of stars common to both tyres and pens. In the diagram, the shaded part represents the region common to stars, tyres, and pens.

Therefore, the number is $$\rightarrow$$ 2

So, from the above, 2 is the only number that represents the stars that are both pens and tyres.

Thus, the correct answer is (a).