A Codebook Contains the Following Information: COLUMNS DESCRIPTION

A codebook contains the following information: COLUMNS DESCRIPTION
1-3 I.D.# (assign each respondent a unique 3-digit ID# from 001 to 851
4 Sex
1=Male
2=Female
5 Class Standing
1=freshman
2=sophomore
3=junior
4=senior
5=transfer
7=don't know
8=no answer
9=refused
Which of the following statements is(are) TRUE concerning the codebook?

A) The variables in this codebook are ID number,sex,and class standing.
B) ID number has been coded so that the categories are mutually exclusive but not exhaustive.
C) Class standing has been coded so that the categories are mutually exclusive and exhaustive.
D) The codebook contains two variables.
E) All of these choices are true.