Question

what do carbon sinks do to carbon dioxide?
release co₂ into the atmosphere
send co₂ away from earth into space
flush co₂ down a drain
extract co₂ from the atmosphere

Explanation:

A carbon sink is a natural or artificial reservoir that accumulates and stores some carbon - containing chemical compound for an indefinite period. By definition, it extracts \(CO_2\) from the atmosphere. Releasing \(CO_2\) into the atmosphere is what carbon sources do. Sending \(CO_2\) into space or flushing it down a drain are not the functions of carbon sinks.

Answer:

Extract \(CO_2\) from the atmosphere.