Institution: SONALI BANK LTD Exam: Sonali Bank Ltd - Sub-Assistant Engineer (Mechanical) - 30.09.2016 ||
Topic: Preposition, Subject: English Grammar (ইংরেজি গ্রামার)

Best Answer Explained in Below-:

The phrase "adhere to" is a commonly used expression in English that means to stick to or remain loyal to a principle, rule, or guideline. In the context of the sentence "You must adhere _____ your principle," the correct preposition is "to" (option A).

Using "adhere to" conveys the idea of commitment and fidelity to a particular standard or belief. It implies that one is not only accepting the principle but also actively following or maintaining it. For instance, in a professional environment, employees are often required to adhere to company policies, meaning they should comply with and uphold those policies consistently.

The other options—"with," "at," and "in"—do not fit semantically with the verb "adhere." "Adhere with" is incorrect because "with" generally implies companionship or association rather than sticking to a principle. "Adhere at" and "adhere in" are also incorrect as they do not establish the necessary relationship between the action of adhering and the principle being referenced.

Thus, "adhere to" is the only choice that accurately captures the intended meaning of commitment to a guiding principle.