The medicine produced an immediate _____.

• A. affect
• B. influence
• C. result
• D. effect

Answer: (D)

Think about the word that names what something causes. After “produced,” you need a noun that means the outcome or result. “Effect” is the standard noun for the outcome produced by a cause, and it fits naturally with “an immediate.” It’s the common way to describe how a medicine changes something right away.

Affect is a verb (to influence), and using it as a noun here isn’t standard. Influence can be a noun, but “an immediate influence” sounds less natural than “an immediate effect” in this context. Result is grammatical and possible, but in medical wording, the usual phrasing is “the medicine produced an immediate effect,” which feels more precise about the actual change caused.