Institution: Bangladesh Public Service Commission (BPSC) Exam: 17th BCS Preliminary Exam 1996
Topic: Correction (Sentence Correction), Subject: English Grammar (ইংরেজি গ্রামার)

Best Answer Explained in Below-:

The term “sluggish” refers to a state of lethargy, lack of energy, or slow movement. When seeking an antonym for “sluggish,” we are looking for a word that conveys the opposite meaning—something that signifies energy, liveliness, or quickness.

Among the provided options, "dull," "heavy," and "slow" do not effectively counteract the connotation of sluggishness. "Dull" suggests a lack of interest or brightness, "heavy" implies weightiness that may lead to lethargy, and "slow" directly aligns with the characteristic of sluggishness, indicating a reduced speed.

On the other hand, the word "animated" describes someone or something that is full of life, energy, or spirited behavior. It suggests quickness, enthusiasm, and a lively disposition, making it the perfect antonym for “sluggish.” By choosing "animated," we highlight a contrast that embodies activity and vigor, thus clearly distinguishing it from the state of being sluggish. Therefore, the best choice to counteract the concept of "sluggish" is indeed "animated."