Explanation:

- We are given that coins are in the ratio 2:3:5 for 25 p, 10 p, and 5 p coins respectively.

- Let the number of 5 p coins be 5x.

- Then the number of 10 p coins is 3x and the number of 25 p coins is 2x.

- Total value in the bag is ?5.25, which is 525 p.

- The equation for the value is: $25(2x)+10(3x)+5(5x)=525$.

- Simplifying gives: $50x+30x+25x=525$.

- Thus, $105x=525$.

- Solving for x, we get $x=5$.

- Therefore, the number of 5 p coins is $5\times 5=25$.

- So, the correct answer is 25.