The correct option is B In spite of
"Because of" in option A is incorrect as it indicates 'as a result of' an action. This does not concur with the context.
"In spite of" in option B is correct. It indicates a contrast between two things. Here, the first factor is doing good work and having manners and the second is not getting a promotion. Both are contrasting things as by good work it follows that one might be promoted. However, as the context refers to not getting promoted, it shows the contrast.
"Even though" in option C also shows a contrast in the subordinate clause. However, here it is incorrect as it indicates a positive result through a negative concept. For instance, we can use it to say that 'even though he did not do good work and was ill mannered he got a promotion'. But as here the concept is positive and result is negative, we use "in spite of" which means the same as although.
"As a result of" in option D is incorrect as it is used to indicate the reason for the action.
Thus, option B is the correct answer.