I believe it would be C. Because taking Kilocalories into account as little as 10% is lost. So if producers have 10,000 kilocalories primary consumers will only obtain 1,000 kilocalories.the secondary consumers which are the frogs in this case will only obtain 100 kilocalories. Once it finally hits the snake or teretitary consumers it only receives 10 kilocalories or 10%
Hope this helps :)
