Which of the Following Are Reasons Why It Is Imperative

Multiple Choice

Which of the following are reasons why it is imperative that marketers determine the just noticeable difference?

A) So that negative changes are not readily discernible to the public and so product improvements are very apparent to consumers without being wastefully extravagant.
B) Product improvements, or negative changes, are not very apparent to customers - just below the j.n.d.
C) Price increases are very apparent to customers - just above the differential threshold.
D) Both (a) and (c) .