Question

Fossils can help us

predict the future

prepare for changes in the environment

respond to changes in the environment

learn how species have changed

Answer 1

The answer that makes the most sense here is to "learn how species have changed".

Because fossils themselves, in a most general sense, are very old, they can't really help our understanding in predicting the future, preparing for environmental changes, or to respond to those changes. They might give us hints as to what the environment was like back then, though, in telling us what plants existed back then and what the dinosaurs may have eaten.

But mainly, they give us a better idea of how species evolved over time allowing us to make connections between them.