This analogy is about the playing area used for a sport. A "pitch" is the specific strip or ground on which cricket is played, so we need the sport whose playing area is called a "ring".
Only boxing uses the word "ring" for its playing area in the same direct way that cricket uses "pitch" for its playing area.
Let's summarize:
So the correct answer is "boxing", option (b).
If the price of a commodity increases by 25%, by what percentage should the consumption be reduced to keep the expenditure the same?