Why does the author provide the information that "in northern Europe the sun may be hidden by clouds for weeks at a time, while temperatures vary not only seasonally but from day to night"?

• To emphasize the variety of environments in which people used sun and water clocks to tell time
• To illustrate the disadvantage of sun and water clocks
• To provide an example of an area where water clocks have an advantage over sun clocks
• To counter the claim that sun and water clocks were used all over Europe

This is a multiple choice.