The correct answer is: No error.
The sentence “No sooner did the sun rise when we took a hasty breakfast and resumed the journey” is grammatically correct. The use of the subordinating conjunction “when” is correct, as it indicates that the action of taking a hasty breakfast happened immediately after the sun rose. The use of the coordinating conjunction “and” is also correct, as it joins two independent clauses together.
The sentence is an example of the “no sooner…than” construction, which is used to express two events that happen very close together in time. In this case, the sun rose, and then the people took a hasty breakfast and resumed their journey. The sentence could also be written as “No sooner had the sun risen than we took a hasty breakfast and resumed the journey.”
The sentence is clear and easy to understand, and it does not contain any errors in grammar or punctuation.