(a) Consider a noisy channel between a sender and a receiver where the data link layer uses CRC (Cyclic Redundancy Check) for error detection based on a 4-bit generator: 1101. If the receiver receives a frame containing bit sequence 111001000, will the frame be discarded by the receiver? Show reasons and details in favor of your answer. A simple answer of yes or no without showing the details will receive no score. (b) Find the number of collisions after which, in CSMA/CD protocol, the NIC can make a binary exponential delay of at most 1536 bit times.