Answer: 1. Formal.
2. Letter
3. Mr. Gallegos’s friends and family who might also be customers and, Your boss.
4. Send news about the promotion recommendation in a separate e-mail.
Explanation:
1. Formal
Although Mr. Gallegos is a long term customer and as such can be spoken to in friendly tones, it is important that Formal tones are used especially as this is a rejection. There should be no room for unseriousness.
2. Out of the options given, a LETTER would be best. This is because the other mediums expressed are instant while a letter is not. The letter will give one the opportunity to properly list reasons why the request was rejected so that the recipient can understand the logic.
3. •Mr. Gallegos’s friends and family who might also be customers and,
•Your boss
Mr Gallegos will likely inform his friends and family who are customers especially because the reply is in the negative to share his disappointment.
As it is an official refusal, your boss would need to be informed of the correspondence as well.
4. Send news about the promotion recommendation in a separate e-mail.
A recommendation for a promotion is a personal thing. It should only be shared with the person affected and as such the recommendation should be sent in a separate email. Sending it separately also reduces discord in the team as they won't feel and murmur like they should have gotten a promotion as well considering they also put in work.