Answer: B. friendly, yet formal; your personality should be evident
Explanation: A cover letter should be in a formal manner in order to gain the impression of a serious and responsible person, but nevertheless friendly, because nobody wants to read the letter overwhelmed with redundant information and incomprehensible phrases and expressions. The personality of the one who writes the letter must be evident so that the employer can see what kind of personality he/she is, and what skills and knowledge he/she has. An impressive choice of words and the wide use of jargon can with the employer cause the impression that the one who writes the letter wants to present himself better than he is. It is necessary to state their skills and how they fit into the needs of the employer, but do not need to overstate them. A familiar tone and word choice as well as slang can give the impression of inalienability and irresponsibility.