Which of the following is NOT a rule that must be followed when naming identifiers?
a) The first character must be one of the letters a-z, A-Z, and underscore or a dollar sign.
b) Identifiers can contain spaces.
c) Uppercase and lowercase characters are distinct.
d) After the first character, you may use the letters a-z, A-Z, the underscore, a dollar sign, or digits 0-9.

Kirk found a local community college with a two-year program and he is comparing the cost with that of an out-of-state two-year school. what is the expected total cost for one year at the local community college if kirk lives at home? what is the expected total cost for one year at the out-of-state school if kirk lives on campus?

Pp 4.1 design and implement a class called sphere that contains instance data that represents the sphere’s diameter. define the sphere constructor to accept and initialize the diameter and include getter and setter methods for the diameter. include methods that calculate and return the volume and surface area of the sphere (see pp 3.5 for the formulas). include a tostring method that returns a one-line description of the sphere. create a driver class called multisphere, whose main method instantiates and updates several sphere objects.

Match the items with their respective descriptions.