Saira begins to sneeze ________ she opens the window to get a breath of fresh air.
Saira begins to sneeze ________ she opens the window to get a breath of fresh air.
Explanation
Whenever is a conjunction which means جب بھی
"Whenever" is the best choice because it indicates that Saira starts sneezing every time she opens the window to get fresh air.
It expresses a habitual or recurring action, making it the most appropriate conjunction for this sentence.