When Coding Data for Computer Analysis,which of the Following Is

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

A) Use only one symbol per column in the computer record.
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 20 possible answers.
D) Use standard codes like "8" for all "No answers" and "9" for all "Don't know" throughout the study.
E) Leave data ungrouped.