Answer:
The answer is indeed letter B) series of events in a story.
Explanation:
Even if we had never heard of the word plot before, we would be able to guess its meaning by using contextual clues. In the sentence "The narrative had a very complex plot or sequence of events and was difficult to follow without stopping frequently to reread", words such as "narrative", "sequence of events", "reread" make it quite clear - and the speaker is practically explaining - that plot refers to a series of events or situation inside a story (narrative).
Anyway, to present a formal definition, plot can be described as the main events of a play, novel, movie, etc. presented in an interconnected sequence by the author.
