Final answer:
Option b) Although tired, she continued to work is a complete sentence.
Step-by-step explanation:
The complete sentence among the given options is b) Although tired, she continued to work.
A complete sentence must have a subject and a predicate, and it should express a complete thought.
In this option, 'Although tired' is the subordinate clause that functions as an adverbial phrase and 'she continued to work' is the main clause that has both a subject ('she') and a predicate ('continued to work').