What is the purpose of Koch's 4th postulate? Selected

Answers:
Identification of capsule forming cells
Test the candidate for infectivity
Test candidates to make sure most subjects develop disease
Monitor cell growth
No answers are correct
Ouestion 6

According to the rna world hypothesis, rna acted as the genetic material and catalyzed reactions in ancient cells. what conclusion can you draw from this?               a.  this implies that dna and proteins aren't essential in cells today.    b.  this implies that rna can catalyze any chemical reaction that enzymes catalyze.    c.  this implies that if a cell has a problem with its dna, its rna can compensate for the damaged dna.    d.  this implies that dna and proteins evolved after rna.