How did a chronometer help European explorers during the Age of Discovery?

It was a navigational tool used to calculate a unit of speed equal to one nautical mile per hour, helping to gauge a ship’s speed.

It was navigational instrument used to measure time and calculate longitude despite weather conditions or motion.

It was a navigational tool used to determine the strength and direction of coastal winds based on a system of levers and pulleys.

It was a navigational tool used to estimate the depth of the sea to pinpoint and notate landmarks across long sea voyages.

I have a feeling is D or B. I'm not completely sure.

4 answers

Which is it. Be sure you know what a chronometer is. That will tell your the correct answer.
is it B? Because a chronometer was basically a watch back then right?
Yes, B. And a chronometer was a clock.
Oh wait, never mind I know now. Thank you! :)