Answer:
volatility...mercurial
Explanation:
The second part of the sentence helps us infer its meaning; it denotes changes in one's mood. From the first part of the sentence, then, we can see that these mood swings mimicked changes in his stock portfolio.
Basically, depending on the balance on his stock portfolio, the person was either ecstatic either depressed.
Now that we've infered the context of the sentence, it's not hard to see that the word pair we're looking for has to do something with changes, variability, inconsistency, tendency to easily fluctuate in short period of the time.
The only pair that could fit in this description is "volatility...mercurial".
Both A&B Identify Modern Architecture.
You will B. Catch up on or D. Study up on
