The correct answer is option 1: "All echinoderms are viviparous".

Dissecting each option:

Option 1 mentions that all echinoderms are viviparous. This is incorrect. Echinoderms, which include starfish and sea urchins, are generally oviparous, meaning that they lay eggs instead of giving birth to live young.

Option 2 says roundworms don`t have a circulatory system. This is true. Roundworms, also known as nematodes, lack a circulatory system and instead depend on a fluid-filled pseudocoelom for nutrient distribution and waste removal.

Option 3 describes that bony fishes usually have swim bladders. This is a fact. Bony fishes, unlike cartilaginous fishes, have a swim bladder, which is an internal gas-filled organ that helps these fish control their buoyancy.

Option 4 states that in cartilaginous fishes, fertilisation is internal. This is correct. Cartilaginous fish, which include sharks and rays, reproduce through internal fertilisation where the male’s sperm is transferred into the female’s body to fertilise her eggs.

In conclusion, the statement that all echinoderms are viv