The answer is D. To answer questions like these, look for numbers that are common multiples of one another: The least common multiple of 7 and 20 is 140 and of 14 and 40 is 280. So they both are equivalent to 140/280 as well. You can also notice that 7 is half of 14 and 20 is half of 40 and get the answer that way too.
