The correct answer is C. Electronic mail.
E-mail is a method of exchanging digital messages, typically consisting of text, but also including attachments that can contain images, files, audio, and video. E-mail, short for electronic mail, is a method of exchanging messages between two or more users. Messages can be sent and received using a variety of devices, including computers, smartphones, and tablets. E-mail is a convenient and efficient way to communicate with others, and it is often used for business, personal, and educational purposes.
Option A, Electric mail, is incorrect because it does not include the word “electronic.” Option B, Electromagnetic mail, is incorrect because it does not include the word “mail.” Option D, None of these, is incorrect because the correct answer is C. Electronic mail.