40. Why are 61 sense codons decoded by only 45 tRNAs? (A) Some tRNAs have anticodons that recognize 4 or more different codons (B) The rules for base pairing between the third base of a codon and tRNA are flexible (C) Many codons are never used, so the tRNAs that recognize them are dispensable (D) The DNA codes for all 61 tRNAs, but some are then destroyed