Professor Thames tried to use a Guttman scale on his data set that he had seen published in a major journal. Thames was upset because the items did not form a Guttman scale on his data. Confused, he asked for your help. You should tell him that:

a. the article that appeared in the journal was probably an error
b. he should recheck his scaling techniques because he probably made an error.
c. items may form a Guttman scale in one sample but not in another.
d. it was probably not a very good scale.
e. none of these choices.