The answer is C. Telegram.
Electricity, telephone, and post are all forms of communication. Electricity is the flow of electrons through a conductor, such as a wire. Telephones allow people to communicate with each other over long distances using sound waves. Post is a system for delivering letters and packages.
Telegrams are a form of communication that was once popular but is now obsolete. Telegrams are messages that are sent over a telegraph wire. Telegraph wires are used to transmit electrical signals, which are then converted into text messages. Telegrams were once a fast and efficient way to communicate, but they have been replaced by other forms of communication, such as email and text messaging.
Here is a brief explanation of each option:
- Electricity is the flow of electrons through a conductor, such as a wire. Electricity is used to power many devices, such as lights, computers, and appliances.
- Telephones allow people to communicate with each other over long distances using sound waves. Telephones work by converting sound waves into electrical signals, which are then transmitted over a wire or through the air.
- Post is a system for delivering letters and packages. Post is used to send mail to people who live in other places. Mail is delivered by mail carriers, who drive or walk to people’s homes and businesses to deliver mail.
I hope this helps!