has remained a dominant communication tool, despite the rise in use of newer, alternative media options for message delivery, because it is a widely available medium for written messages with which users are comfortable.

E-mails

Explanation:

 An E-mails is one of the type of digital message and also known as the dominant communication tool which is used for in the form of document in an organization where we can used it in different ways are as follows:

According to the given question, Emails is one of the type of tool that is used as the communication medium and it is one of the flexible message delivery options which is widely used by an organizations.

a.s= 230t– 110; 1500 lbc.t= 230s– 110; 1500 lbb.s= 230t+ 110; 1720 lbd.s= 199t– 110; 1280 lb