Which of the Following Statements About Marketing Mixes Is True

Which of the following statements about marketing mixes is True?

A) Each marketing mix element contains one and only one variable.
B) The four marketing-mix elements are promotion, distribution, price, and advertising.
C) Marketing-mix elements are interrelated.
D) Decisions about one element of the marketing mix seldom affect other elements.
E) Price is the only element of the marketing mix that cannot be used by itself as a basis for competition.