This is a trick question playing on wording. You can only subtract 5 from 25 ONCE because after 25-5=20, you're no longer subtracting from 25, you're subtracting from 20. Many people mistakenly think it's 5 times (25, 20, 15, 10, 5, 0) but the question asks how many times you can subtract FROM 25 specifically. The claimed answer A (1 time) is correct for this word puzzle.