Which technology allows for increased data transfer rates by using multiple channels?

The correct answer is bandwidth aggregation because it specifically refers to the technique of combining multiple channels to increase data transfer rates. This approach takes advantage of the available bandwidth of different connections, effectively creating a faster and more reliable data transmission experience. By pooling resources from multiple sources, bandwidth aggregation can enhance network performance, allowing users to experience higher speeds than what a single channel could provide.

In contrast, ISDN (Integrated Services Digital Network) is a traditional telecommunications method that transmits voice and data over the same lines but does not inherently combine multiple channels to increase speeds in the same manner. DSL (Digital Subscriber Line) provides high-speed internet access through telephone lines, but it does not employ aggregation techniques. Fiber optics is a technology that uses light to transmit data, which offers high bandwidth capabilities but is not itself a method of aggregating multiple channels together for increased speeds. Bandwidth aggregation stands out as the specific solution designed for that purpose, making it the best answer in this context.