a solid, a liquid, and a gas (vapor) a solid and a liquid a solid and a gas (vapor) a solid only
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: A hydrologist studies the location, movement, and quality of water. A hydrologist recognizes the importance that water exists as ___.
Possibilities:
- a solid, a liquid, and a gas (vapor)
- a solid and a liquid
- a solid and a gas (vapor)
- a solid only

a solid, a liquid, and a gas (vapor)