Suppose the sphere packing bound from Lemma 4.9 was C < 2" /(n + 2) instead of |C| < 2" /(n + 1). Select all that would now be true. a) n=7 would no longer be a valid solution for k-4. | b) n=6 would be a valid solution for k=4. Oc) n=8 would be a valid solution for k-4. d) this would mean we could possibly find codes with higher/better rate e) this would contradict the fact that the Hamming code for k=4 has rate 4/7.