Metabolism using an electron transport system is classified based on the nature of the initial electron donors and terminal electron acceptors. Lithotrophy uses molecules as the electron .

Lithotrophy uses inorganic molecules as the initial electron donors.

Explanation:

Lithotrophy is also referred to as chemolithotrophy is a diverse group of organisms using inorganic substrate of mineral origin to obtain reducing equivalents for use in biosynthesis or energy conservation. It acquires energy by oxidation of inorganic electron donors, although electron acceptors may be organic or inorganic. Lithotrophy uses inorganic molecules as the initial electron donors.

the sea slugs belong to the same class

a, i am pretty sure.