D would be the answer to this question
Lunar maria (plural form of the Latin word mare, which means sea) are dark surfaces that can be found all over the moon (17% of the Moon is covered in them) that have been created as a result of volcanic eruptions. These areas are made up of basalt, and given that they seemed almost waterlike, the astronomers in the distant past mistook them for seas, whence their name comes.
When it comes to craters, their origin is quite similar - volcanic eruptions created them. When lava starts erupting from a volcano, it has to get out from somewhere - and thus craters are created. If you are referring to lunar craters, however, there are many speculations as to how they were created: due to volcanic eruptions, meteoric impact, or glacier activity.
Answer:
A fall-arrest system should be worn while climbing a tree or any tall structure. This will enable the person to have a thing to break or slow his fall if he loses his grasp from the trunk of the tree.
Explanation:
Safranin is used to prepare an onion peel slide. Explanation: We use this strain because this strain can differentiate the region of the cells darker than the other regions.