Which sentence from the selection best conveys the central idea?
A) Ecological mapping gives researchers insight into living things and their habitats.
B) The scientists turn, retreating to the safety of the laboratory onboard.
C) The ecology of the shelf includes biological elements, like animals.
D) The speed of sound in seawater depends on temperature, salinity, and depth.
The correct answer is A) Ecological mapping gives researchers insight into living things and their habitats.
Explanation: This sentence best conveys the central idea because it highlights the main purpose of ecological mapping, which is to provide important information about the relationships between living organisms and their environments. The other options either offer specific details or describe actions that do not capture the overarching theme.