Explanation:

- Option 1: Lipids

- Lipids are fats and oils.

- They are not water holding.

- Common in seeds and cell membranes.

- Option 2: Carbohydrates

- Carbohydrates include sugars and starches.

- They provide energy.

- Not all are water holding.

- Option 3: Hydrocolloids

- Produced by marine brown and red algae.

- Used as thickeners and stabilizers.

- Substances like agar and alginate.

- Correct answer.

- Option 4: Gelatin

- Derived from animal collagen.

- Used in desserts and pharmaceuticals.

- Not from algae.