What effect does multi-path propagation have on data transmissions?

Multi-path propagation occurs when a radio signal reaches the receiving antenna via two or more different paths, such as bouncing off buildings or hills. Because these paths are of different lengths, the signals arrive at slightly different times, causing them to interfere with one another. In data transmissions, this time delay (multipath spread) distorts the digital symbols, making it difficult for the receiver's decoder to distinguish between ones and zeros. Consequently, this interference causes data error rates to increase. The options suggesting a calculated change in transmission rates based on the number of paths are simply distractor formulas with no basis in actual radio operation.