What are the four main classes of large molecules in living things?

All organisms need four types of organic molecules: nucleic acids, proteins, carbohydrates and lipids; life cannot exist if any of these molecules are missing.

1. carbohydrates

2. lipids

3. proteins

4. nucleic acids

Explanation:

kelp are large brown algae that live in cool, relatively shallow waters close to the shore. they grow in dense groupings much like a forest on land. these underwater towers of kelp provide food and shelter for thousands of fish, invertebrates, and marine mammal species.

e) all of the above

i think its both a and b