Final answer:
The correct answer regarding the effects of Coronal Mass Ejections (CMEs) is b) Aurora borealis (Northern Lights). CMEs can cause these lights by sending charged particles towards the Earth's poles, where they produce colorful displays in the atmosphere.
Step-by-step explanation:
Coronal Mass Ejections (CMEs) from the Sun can have various effects on Earth, but the one that is directly observable is the Aurora borealis (Northern Lights). CMEs involve immense quantities of solar material, mainly protons and electrons, being ejected at high speeds. When these charged particles interact with the Earth's magnetosphere, they travel along magnetic field lines to the poles, where they collide with particles in the Earth's atmosphere. This collision causes a display of lights that can span a large part of the sky, creating the spectacular auroras known as the Northern Lights and the Southern Lights (Aurora Australis).
On a more disruptive note, when coronal material from a CME reaches Earth, it can heat the ionosphere causing it to expand. This expansion increases friction between the atmosphere and orbiting spacecraft, potentially dragging satellites to lower altitudes and adversely affecting their operation. However, CMEs do not cause an increase in atmospheric pressure, a reduction in Earth's gravitational pull, or a decrease in ocean salinity.