Answer:
The correct answer to the following question will be "Create and send a newsletter".
Step-by-step explanation:
Newsletter: A newsletter is a paper or electronic publication that includes news about a company or an organization's activities that are circulated to its members, clients, employees or other subscribers.
The newsletter helps n sharing important information between employees, for example, new training procedures and providing relevant branch information and updates to help the workers excellently perform their duties.
Business letter: It is an official document that is usually sent to customers, staff, and stakeholders from one organization to another or from one corporation.
Call each employee: As 3000 employees are working in the organization(according to the question), so it is hard to call each employee and tell him about the update.
Send another e-mail: As some of the employees didn't even read the previous mail, so sending another mail is not an appropriate option.
Hence, Carl should create and send the newsletter.