The giant marine alga Halicystis ovalis is able to move sodium ions from vacuoles to the surrounding seawater through active transport. Which condition or feature is required for this mode of transport

Two very important conditions are required.

-Energy

-Concentration gradient

Explanation:

The conditions are as follows:

-It requires an energy source such as ATP

-The transport must always be carried out from a gradient from higher concentration to lower concentration or vice versa.

i think its the first one