What is the science of getting ships from place to place, including the determining of position, course and distance traveled?
a) navigation
b) monopoly
c) mercantilism
d) astronomy

The science of getting ships from one place to another place is A - Navigation.

Monopoly refers to an economic condition where one big company owns the majority market
Mercantilism refers to an economic system that was used a few centuries ago. 
Astronomy refers to the study of celestial objects.

Hold on to his or her beliefs even if there is no evidence for those beliefs.