Backbone around the world is connected through:

Explanation

The answer is (d) All of these. The backbone of the internet is the high-speed infrastructure that connects major networks around the world. This infrastructure uses a combination of technologies, including:Undersea cables: These are fiber optic cables laid on the ocean floor to carry data traffic between continents.Satellite links: Satellites can be used to provide internet connectivity to remote areas or for backup purposes. However, satellite links typically have higher latency (delay) compared to undersea cables or fiber optics.Fiber optic cables: Fiber optic cables are made of glass fibers that transmit data using light pulses. They offer very high bandwidth and low latency, making them ideal for carrying large amounts of data traffic.