Flow control methods prevent network congestion by:

Flow control methods are essential in networking as they manage the rate of data transmission between sender and receiver to prevent the sender from overwhelming the receiver with too much data too quickly. This directly addresses network congestion, which can occur when too much data is being sent for the receiving device to process efficiently. By regulating the flow of data, flow control ensures that the receiving device can handle incoming information, thereby maintaining optimal performance and preventing data loss or delays.

The other options come into play in different aspects of data transmission and network reliability but do not directly relate to the concept of flow control. For example, establishing a window in the error table pertains more to error management rather than controlling the flow of data to prevent congestion. Similarly, determining if transmitted data is corrupt focuses on the integrity of the data rather than managing how much data is being sent at once. Finally, sending data through redundant paths is about ensuring reliability and availability of data paths rather than controlling the volume of data sent to avoid congestion.