Professor Thames used a Guttman scale on his data set that he had seen published in a major journal. ...

Professor Thames used a Guttman scale on his data set that he had seen published in a major journal. Thames was upset because the items did not scale on his data. Confused, he asked for your help. You should tell him
 
  a. the article that appeared in the journal was probably in error.
  b. he should recheck his scaling techniques because he probably made an error.
  c. items may form a Guttman scale in one data but not in another.
  d. it was probably not a very good scale.
  e. the article that appeared in the journal was probably in error and therefore it was probably not a very good scale.