Why was Samuel Johnson unhappy with Lord Chesterfield?

A. Lord Chesterfield had written unfavorable reviews of Samuel Johnson's work.
B. Lord Chesterfield had written a competing dictionary after promising that he would not do so.
C. Lord Chesterfield was behaving as if he had been a valuable patron of Samuel Johnson.
D. Lord Chesterfield refused to publish Samuel Johnson's dictionary without a sizable advance payment.

Wasn't paying attention. RIp