Answer the following question given this paragraph: 

The earliest plants are thought to have evolved in the ocean from a green alga ancestor. Plants were among the earliest organisms to leave the water and colonize land. The evolution of vascular tissues allowed plants to grow larger and thrive on land. The evolution of seeds and pollen allowed them to reproduce on land without moisture. Flowering plants evolved flowers with ovaries that formed fruits. They have been the most successful plants of all.


Q: From where have the earliest ocean plants thought to have evolved?

 Choices:

- green pepinia ancestor

- simple coral ancestor

- simple alga ancestor

- green alga ancestor

A:
green alga ancestor
