A. lackadaisical
B. active
C. dull
D. persistent

Explanation:

The word quiescent means inactive, quiet, or not moving.

In simple words: in a resting or sleeping state, with no activity.

The opposite of quiescent is active, which means busy, energetic, and full of movement or activity.

So, Active is the correct antonym of Quiescent.

Real-Life Example

Imagine two situations:

• A volcano that is not erupting and is completely calm → this is quiescent.
• A volcano that is erupting and showing strong activity → this is active.

Inactive = Quiescent
Energetic = Active

Main Points for Exams

• Quiescent means inactive, still, or at rest.
• It is often used in science, biology, and general English.
• Active means energetic and in motion.
• Lackadaisical is similar to quiescent, not opposite.
• Therefore, Active is the correct antonym of Quiescent.
• This type of vocabulary question is common in PPSC, FPSC, CSS, PMS, NTS, IELTS, TOEFL, and other competitive exams.

Quick Memory Trick

😴 Quiescent = Sleeping / Still
⚡ Active = Moving / Energetic

Rest ↔ Movement
Quiescent ↔ Active ✔️