Which two functions does a codebook serve?

It keeps track of determining how many cases are coded and serves as the primary guide used in the coding process.

It serves as the primary guide used in the coding process and serves as a guide for locating variables and interpreting codes.

It serves as a guide for locating variables and interpreting codes, and keeps track of how many respondents exist.

It keeps track of how many respondents exist and keeps track of determining how many cases are coded.