In the first paragraph, the author mentions McKendrick and Plumb most probably in order to ______.

A．contrast their views on the luxury consumerism in eighteenth-century England
B．indicate the inadequacy of the traditional approaches to eighteenth-century English history
C．support the contention that key questions about eighteenth-century consumerism remain unanswered
D．give examples of historians who have explored the eighteenth-century consumerism in England