Hector works for a renewable energy company but was recently fired. He did his job better than any of the other workers in his department, but he often refused to help others with their work. Hector did his work well but never did anything extra. He called in sick many times and missed work twice without calling to inform his boss. He also did not like being told how to do things and got angry when criticized by the boss. Hector was probably fired because
a. He was not skilled at his job
b. He lacked technical expertise
c. He had attendance issues and poor teamwork
d. He was too cooperative with others