It's a potentially confusing question, because the 40:30:30 ratio in the stem is the ratio of the "daily calories" from each source, while the numbers in Statement 1 are measured in grams, not in calories. So at first glance, looking at Statement 1, it might seem Bill followed the diet exactly for that one meal, but he wasn't even close to following the diet -- if you use the calorie conversions mentioned at the end of the stem, he ate 320 calories of carbohydrates, 240 calories of protein, and 540 calories of fat, so nearly 50% of his calories came from fat, instead of the 30% the diet requires.

Statement 1 isn't sufficient though, because he could have eaten twelve other meals that day, and with no information about those meals, we have no clue if he followed the diet. Statement 2 isn't sufficient alone either, because we have no idea what Bill ate. Using both Statements, if his diet requires exactly 30% of his calories to come from fat, then if he follows the diet, and eats 1500 calories total, he eats 450 calories from fat. But as we saw above, Statement 1 tells us in just one meal Bill ate 540 calories of fat, so there's no chance that he followed the diet, and the answer is C.