Select the most appropriate synonym of the highlighted word.
Since the last few hours his pulse rate is constant.

Correct option is A

The correct synonym of the given word is (a) Steady.

Given word (constant): Happening regularly or remaining the same over time; not changing (स्थिर/निरंतर). It conveys uniformity and lack of fluctuation.
Example (given word): Her support remained constant during the entire recovery period.

Correct answer word (steady): Firm, regular, even, and not changing suddenly (स्थिर/संतुलित/नियमित). It closely matches “constant” in sense of unvarying rate or level.
Example (synonym): The patient showed a steady improvement in vital signs.

Synonyms: stable, steady, consistent, uniform.
Antonyms: variable, fickle, fluctuating, inconstant.

Meanings of all the other given options:
· (b) Fickle: Changing frequently, especially in feelings or loyalties (चंचल/अस्थिर)
· (c) Pitiful: Deserving or arousing pity; very poor in quality (दयनीय)
· (d) Reflective: Given to deep thought; capable of reflecting light (चिंतनशील/परावर्तक)