Which of the Following Is a True Statement

Which of the following is a true statement?

A) Since marketing is concerned with many thousands of different products, there is no one set of marketing functions that applies to all products.
B) Responsibility for performing marketing functions can be shifted and shared, but no function can be completely eliminated.
C) From a micro viewpoint, every firm must perform all of the marketing functions.
D) Marketing functions should be performed only by marketing intermediaries or collaborators.
E) Many marketing functions are not necessary in market-directed economies.