Question

You have been traveling all day. You -------------------be very tired
(a) could
(b)must
(c)can
(d)must have​

Answer 1

Answer:

must is correct answer...

HAVE A NICE DAY

Answer 2

You have been traveling all day. You must be very tired.

Answer: Option (b)

Explanation:

A ‘modal’ is a verb that implies any emotion or mood like permission, order, request etc. In this sentence 'must' has been used as the modal. Must is a logical thinking modal.

It is the modal that implies that it is a logical inference from any argument. Here we can logically derive that the listener is tired because he had been travelling the entire day. So must is the right answer in this given sentence.