Option 1 states that the food cycle starts with a frog, then moves to a grasshopper, followed by a snake, and ends with a vulture. This food cycle is incorrect because a frog does not eat grasshoppers, so it would not fit in this sequence.

Option 2 presents the correct food cycle. It begins with a grasshopper, which is eaten by a frog. The frog is then eaten by a snake, which is in turn eaten by a vulture. This sequence follows the natural order of a food chain, with each organism being eaten by the next.

Option 3 states that the food cycle starts with a frog, followed by a snake, then a grasshopper, and ends with a vulture. This sequence is incorrect because snakes do not eat frogs, so the order is not accurate.

Option 4 states that the food cycle begins with a grasshopper, followed by a snake, then a vulture, and ends with a frog. This cycle is incorrect because vultures do not eat snakes, which means this sequence is not valid.

Therefore, the correct food cycle is option 2, where the sequence is: grasshopper, frog, snake, vulture.