Select whichever preposition or determiner you consider the most appropriate for the blank space.
Shalini usually goes to work________ bus.

Correct option is B

The word that can be filled in the blank is ‘by’ to make the sentence grammatically and contextually correct.
• ‘By’ is often used when referring to travel by instruments or vehicles.
• As per the context, the word ‘by’ fits very well & hence, it is the correct option.
Meanings of other given words:
• On - typically used to indicate position above and supported by or in contact with.
• At - used to indicate a specific time.
• With - used to indicate the instrument used to perform an action.
• Thus, all the other given words have different meanings and do not fit in the context of the sentence.