The correct answer is alternative one.
At the time of evaluating a source for credibility, it is important to find out the author's qualifications, achievements, personal quality or his or her background, in order to indicate if he or she is a suitable source of reliability.
Regarding bias, another source for author integrity has to do with unfair prejudices in favour or against something, a person or group.
Finally, it is essential to know the reasons for writing the source. As a result, all these reasons are fundamental when considering the credibility of a source.
