A Research Firm Was Using Fishbein's Model to Measure Attitudes

A research firm was using Fishbein's model to measure attitudes, but found that the predictions of the model were insufficient to explain the behaviour of their client's customers. The firm decided to try the extended Fishbein model; what did they need to add to their original research?

A) They needed to add an attitude- tracking program
B) The social class and the income of the average customer
C) The age and income of the average customer
D) They needed to identify the important attributes that their client's customers consider when evaluating the product
E) They needed to add the influence of an individual's attitude toward the act of buying