Question

Select the most appropriate word that can substitute the underlined word in the given sentence without altering the sentence's meaning.

The professor’s lecture on quantum mechanics was as enlightening as it was challenging.

• A. confusing
• B. illuminating
• C. perplex
• D. dull

Answer 1

Answer:

B. illuminating

Sentence:

The professor’s lecture on quantum mechanics was as enlightening as it was challenging.

Explanation:

Enlightening means:

Informative, educational, illuminating, giving greater understanding or knowledge.

So the best substitute is:

✅ illuminating = enlightening

Why the others are incorrect?

• confusing ❌ = difficult to understand (opposite meaning)

• perplex ❌ = to confuse; also a verb, not suitable here

• dull ❌ = boring, uninteresting (opposite meaning)