Topic: Conditional Sentence,

Best Answer Explained in Below-:

The question "If you go to Chittagong, where -?" requires a response that fits the conditional structure of the phrase. Each option proposes a different grammatical structure, but "C) shall you stay" stands out as the most appropriate choice.

When forming conditional sentences starting with "If," we often contemplate situations that are hypothetical or uncertain. The phrase "If you go to Chittagong" introduces such a hypothetical scenario. In response, "shall you stay" effectively adheres to the structure of a conventional inquiry about future actions, particularly in British English. Here, "shall" conveys a sense of necessity or expectation regarding the subject's future decision to stay, framed within the context of the conditional setup.

Conversely, while "would" is often used in conditional phrases, option "B" isn't suitable because it lacks the inversion necessary in a question format. Similarly, "A" is less formal and doesn't maintain the inquiry's conditional implications, and "D" uses "shall" incorrectly in a statement form. Thus, "C) shall you stay" correctly matches the conditional context and the interrogative structure, making it the best answer.