Answer:
A. acting as a positive source derogation.
Explanation:
Source derogation is a behavior pattern of people when they start disbelieving not only the content of message but also the trustworthiness of source of message. They start suspecting the  credibility of message .
In the present case , there is need to make sure that people start reposing confidence in the statement by the company because the very reputation of the company is at state because of fatal accident .
Mr Murphy will act as positive source derogation , building confidence of people in what company say in public and thus reduce rumours or negative
advertisement by competitors.