1. 

TRANSIENT
A. Transparent
B. Fleeting
C. Feeble
D. Fanciful

Answer: Option B

Explanation:

Meanings of the given words:

Transient : means very short time of any phenomenon.
 i.e. we say transient analysis.

Transparent : means easy to perceive or detect.
Synonyms : obvious, explicit, clear, lucid etc.

Fleeting : means something which happens for a short duration.

Feeble : means lacking physical strength, especially as a result of age or illness.


Fanciful : means not believable.

So, Fleeting  is the correct answer.