Most enzymes are proteins. However, some ribonucleic
acid (RNA) molecules have been known to display
enzymatic activity toward other RNA molecules.
What type of behavior did these RNA molecules most likely exhibit in order to
be classified as enzymes?
A. Forming branched molecules that store energy
B. Catalyzing chemical reactions
C. Attacking foreign substances and marking them for destruction
D. Attaching themselves to a strand of DNA and making a copy