The correct answer is B. obstinate.
An obstinate person is someone who is stubbornly unwilling to change their opinion or behavior. They may be difficult to reason with and may often refuse to cooperate with others.
The other options are not as accurate descriptions of someone who is obstinate. A conciliatory person is someone who is willing to compromise or make concessions in order to reach an agreement. A sympathetic person is someone who feels or shows pity or compassion for others. A courteous person is someone who is polite and respectful.
In the context of the question, it is clear that the person in question was not willing to compromise or make concessions, and they were not feeling or showing pity or compassion for others. They were also not being polite or respectful. Therefore, the most accurate description of their attitude is obstinate.