I would say D. a name given to the system of lines used to locate points on earths surface
Explanation:
A quick google search of a graticule explained that it is a network of lines representing meridians and parallels on which a map or plan can be represented.
An estimated 50-80% of all life on earth is found under the ocean surface and the oceans contain 99% of the living space on the planet. Less than 10% of that space has been explored by humans.
