Joe is an excellent programmer. He was promoted to a role of Project Manager because he understands technology better ?

C. Halo Effect

Joe has been given a role on the assumption that his excellent technical skills as a programmer will make him succeed in a managerial role.  He is ill matched for the new role therefore failing.

It is an example of a Halo Effect judgment. He was only seen with an excellent skill without considering other factors on the new role of Project Manager. Some people are excellent on their skills but still needs to be trained to handle higher positions.

Halo Effect. As most of the persons can not be excellent in more than one dissiplines. Same is the case mentioned in the question, Joe was an excellent programmer but he was not good in Project Management and was promoted to that position. If someone is to be promotied to specific position, his/her abilities must be checked according to the new role JD's. If he/she is not capeable to fulfil that position, in this case, the organisation must find some other persor or should polish the skills of that person so that he can be promoted.

Excellent programmer is a specialist called techinial professional; he may have have some basic management knowledge, with it he can manage any project up to certain extent by learning stage by stage but we can't expect efficiency in all aspects. 

We need a Management expert called generalist who is well trained to manage any thing. Generalists have adequate management expertise to administer any project effectively and efficiently. Because managemen expert called generalist is trained in the fields of mangement to achieve any project with cost and time efficiency. Generalists know even how to use expertise of the professionals for the success of the projects.

The real fact is, a Management proficient called generalist is better than a Programmer or specialist of programming professional to manage any project efficiently. 

Therefore, we conclude that promoting a programmer to a Project Manager is not a wise decision. Suitable person is a management professional called generalist or Administrator.

Answer: CExplanation: The halo effect is when you put someone in a position they can't handle, just because they're good at another job. Just because Joe is a great programmer, that doesn't mean he'll be a good Project Manager.