let us look at each answer option -
A states that - interest rates were not nearly as high as the early 1980s. this option compares interest rates to 1980s.
B - Correct answer.
C - "at the time + when" is redundant.
D - Usage of past perfect is incorrect. We are referring to a specific point in the past - "last year". Use past tense. "during the time in which" is clearly inefficient compared to "when"
E - the usage of passive voice is vague. the high levels were not being approached by what? Then "when" is also very far from the noun it must modify - 1980s.

Even though interest rate rose last year, they were not nearly as high as the early 1980s, when the economy tumbled into a recession and markets were depressed.

A) they were not nearly as high as the early 1980s, when
wrong comparisons
interest rate with 1980

B) they were not nearly as high as interest rates in the early 1980s, when
correct

C) they were not nearly at the levels they were in the early 1980s, at the time when
at the time and when redundant
referent of they is missing

D) they had not approached the high levels of the early 1980s, during the time in which
wrong tense: had
during the time in which is wordy, when is better

E) the high levels of the early 1980s were not being approached, when
wrong comparison
high levels of what?

Hi Experts ,

I was reviewing this question.

In A is this possible that INTEREST RATES is omitted, but the presence is implied?

A) they were not nearly as high as the [ INTEREST RATES] early 1980s, when....

Please explain.

Many thanks in advance.

Kavin