You can find other articles to see if they have the same information. Do your research on the topic at hand, in other words.
Answer:
Having hope is motivation for an human being. Something they can hold onto. Hope allows people to approach problems with a mindset and strategy-set suitable to success, thereby increasing the chances they will actually accomplish their goals. ... Hope-related cognitions are important. Hope leads to learning goals, which are conducive to growth and improvement.
I am going with B because using a phone call, the customer can notice emotion, if you send a text or something, the person won't know if you actually mean the apologies. Hope i helped. Have a nice day.