The word "alight" has multiple meanings depending on context:
• As a verb, "alight" means to step down or descend from a vehicle or other elevated position (Sentence I).
• As a verb, "alight on" means to notice or discover something by chance (Sentence II).
• As an adjective, "alight" means burning or illuminated, but in Sentence III, "was alighted" is incorrect; the correct phrasing should be "The house was set alight" or "The house was ablaze."
Since only sentences I and II correctly use "alight," the correct answer is option (d).