(a) purchase DUK, but not KO. (b) purchase KO, but not DUK. (c) purchase both KO and DUK. (d) purchase neither KO nor DUK. A (8) Text: Chapter 6, Question 8, Section 6.11, p. 239. Investing with retained earnings will always be the optimal strategy if feasible, but Zeno Corporation's samings fall short of the mark in terms of being able to easily rainvest $100 00o