Question

which of the following are valid variable names? select 2 options. cost$4 4thnumber num4 $4cost fourth_number

Explanation:

In most programming languages, variable names must start with a letter or an underscore, and can be followed by any number of letters, digits, or underscores. 'cost$4' and '$4cost' have a dollar - sign which may not be allowed in some languages. '4thNumber' starts with a digit which is usually not allowed. 'num4' and 'fourth_number' follow the naming rules.

Answer:

C. num4, F. fourth_number