Macbeth, Romeo and Juliet, and Hamlet.
The letter a would be the bast answer
Interesting... it has to be able to capture the readers attention and keep them thinking even when they are done with your essay
The author here is describing, in a sequential or chronological way, a series of events that took place in the past (hence the use of the past tense), namely: 1) "...he finally convinced...", 2) "Early results were not..." and 3) "...but... customers became hooked."