Fill in the blank with an appropriate option.
Lecanemab was recently reported to have a small but ______ effect in reducing cognitive decline.

Correct option is D

The correct option to fill in the blank is (d) Marginal.
Explanation: The phrase "small but ____ effect" suggests a minimal positive impact. “Marginal” means small or slight. (बहुत कम या सीमांत)
Example: The policy had only a marginal impact on inflation.
Other options:
· (a) Microscopic: Extremely small (सूक्ष्म) – used more for size than effect.
· (b) Significant: Not small (महत्वपूर्ण) – opposite to “small but”
· (c) Optional: Not mandatory (वैकल्पिक) – unrelated to context