Explanation:

- Annelida: This group includes segmented worms. They lack a notochord, placing them under non-chordates.

- Porifera: Known as sponges, these are simple organisms without a backbone. They also fall under non-chordates.

- Vertebrata: This subphylum includes all animals with a backbone, such as humans, birds, and fish. They are part of the chordates.

- Mollusca: Consisting of snails, clams, and squids, they lack a notochord and are classified as non-chordates.

Correct Answer: Option 3, Vertebrata