B. Sharp mental acuity
Mental acuity refers to being mentally sharp. If you're mentally sharp, you have an excellent memory, and you find it easy to complete different tasks. Lack of sleep can effect this.
The closest distance between the orbits of these two planets is about 24 million miles. But the actual distance between the two is constantly changing because they orbit the sun at different speeds. At the farthest, these two planets are 162 million miles apart.
Decomposers are necessary to the food chain because they break down the results of the food chain into the basic elements that producers can then use to begin the process over again. Decomposers include groups of bacteria that help to speed up the decaying process of dead plants and animals.
Hope that helped! =)