4B5B differs from line coding techniques in that is ensures that strings of consecutive "1s" and "0s" do not exist prior to the data being line coded. Select the correct statement(s) regarding 4B5B. a. since 4B5B eliminates long string of logical "1s" and "0s", simpler line coding techniques such as NRZ can be used. b. since one bit out of every five bits sent is not real information, the data link suffers from a 1/5 or 20% overhead cost (i. e., reduction in information data throughput) c. only 80% of the data sent using 4B5B is real information d. all of the above are correct statements