Explanation:

The correct answer is option 'B' (Fleeting).

Definition of Transient:
Transient is an adjective that describes something as not lasting long, or something that is temporary or short-lived. It refers to a state or condition that is brief and quickly passing.

Explanation of the options:
To understand why option 'B' (Fleeting) is the correct answer, let's look at the meanings of the other options:

a) Transparent:
Transparent is an adjective that describes something as clear, easy to see through, or easily understood. It does not convey the meaning of something being temporary or short-lived, so it is not the correct answer.

b) Fleeting:
Fleeting is an adjective that means lasting for a very short time, transient, or passing quickly. This option is the correct answer because it aligns with the definition of "transient" as something that is temporary or short-lived.

c) Feeble:
Feeble is an adjective that describes something as weak, lacking strength or vigor. While it may convey a sense of transience in some contexts, it does not directly mean something that is temporary or short-lived, so it is not the correct answer.

d) Fanciful:
Fanciful is an adjective that describes something as imaginative, whimsical, or unrealistic. It does not convey the meaning of something being temporary or short-lived, so it is not the correct answer.

Conclusion:
Among the given options, only option 'B' (Fleeting) aligns with the meaning of "transient" as something that is temporary or short-lived. Therefore, option 'B' is the correct answer.