单项选择题

Nathan was a fiercely ambitious and competitive man, as quick to take offence as to give it in his business dealings, and it is not difficult to imagine him responding ______to such______.

A. mysteriously … an entreaty
B. fractiously … a pleasantry
C. self-effacingly … an invitation
D. impetuously … a contretemps
E. gravely … a leitmotif