Which invention by Alexander Graham Bell revolutionized communication?

The invention by Alexander Graham Bell that revolutionized communication is the telephone. Introduced in the late 19th century, the telephone allowed for voice communication over long distances, fundamentally changing how people interact. Prior to the telephone, most communication relied on written forms such as letters or telegraphs, which only could transmit text without the immediacy of voice. The telephone enabled real-time conversations, which provided a more personal touch and facilitated business communications significantly.

The other options represent important inventions as well but do not pertain to Bell's contributions. The television, developed later, transformed visual media by enabling the transmission of moving images and sound. The telegraph, although a critical development in its own right, provided only text communication using electrical signals. The phonograph, invented by Thomas Edison, was the first device to record and reproduce sound but did not directly involve two-way communication like the telephone. Thus, the telephone stands out as Bell's defining invention that reshaped communication methods for society.