What is the average mass of an electron? a. 1 amu b. 1,837 amu c. 1/1,837 amu

Idon’t quite understand this problem

The charge on a charged sphere is: a)concentrated at its centerb)distributed uniformly throughout its volumec)clustered on its centerd)distributed uniformly over its surface

What is a carrier wave and how does it affect what you hear on the radio