When Coding Data for Computer Analysis, Which of the Following

When coding data for computer analysis, which of the following is NOT recommended?

A) Use only one character per record column.
B) Use alphabetic characters.
C) Assign as many columns to a variable as is necessary to capture the variable, e.g., two columns would need to be assigned to a question with 12 possible answers.
D) Use standard codes like "8" for all "no answers" and "9" for all "don't knows" throughout the study.
E) Each of these procedures is recommended.