The 4th one
Explanation
He is done talking.
Adverb phrases modify the verbs and say how something is done, or when, or why.
Here it's <span>d. quickly and safely
- the action (flipping) was done </span><span>quickly and safely
</span>
....................WHEN?!?
They were better off. Without the discovery of the uses of fire, mankind would not be here. Fire led to the rapid increase of newer, more advanced tech, such as a sword instead of a club.
