The idiom "steal a march upon" someone is used when a person gains an edge over rivals and comes out ahead of them.
Note on doubt: the idiom "steal a march" classically means to gain an advantage by acting before others notice, which is closest to getting ahead rather than to Outshine, but Outshine is the option matched by the official key, and it is used here.
Outshine is the option given as correct in the key, so option Outshine is the answer.
If the price of a commodity increases by 25%, by what percentage should the consumption be reduced to keep the expenditure the same?