Many scientists believe that the dinosaurs disappeared as the result of which of the following

ANSWER:

There are enough facts to prove that the dinosaurs disappeared as the result of asteroid impacts.

EXPLANATION:

Back around 65 million years ago, these asteroids rained down upon Earth bringing destruction and global extinction of almost all species thriving on this planet. Dinosaurs roamed the Earth for nearly about 165 million years. The impact further triggered earthquakes, tsunamis, and super-volcanoes which brought further devastation. The sun was completely blocked off with thick layers of smoke which cause the ice age. In the ice age, the condition was so harsh that nothing was able to grow and thrive on the surface of the earth. This led to the shortage of food for the Dinosaurs resulting in their complete extinction.

The study of where things are 

The sun's parallax would be 180 degrees, greater than which you can't get.  so a. would be your anwser