Select the correct meaning of the underlined word in the sentence given below:-

His desultory efforts at studying made it clear that he was not serious about passing the exam.

unenthusiastic

The correct answer is Option (4) → unenthusiastic

Desultory means lacking a plan, purpose, or enthusiasm; done without a particular pattern or order. When applied to efforts, it suggests they are half-hearted, aimless, or unfocused. 

• Cautious – means careful or avoiding risk; unrelated in this context.

• Impetuous – means acting quickly without thought; not a fit here.

• Guileful – means deceitful or sly; not relevant to the idea of effort or enthusiasm.