Hi it's C.pines
hope it helps
As covalent bonds are strong it makes the sugar phosphate backbone a stable molecule which will HV less chances for a mutation while the huydrogen bonds exist for the ease of DNA replication as they are strong in a way but weak for the replication to take place easily.
D is the correct answer :)
Question 1: im not completely sure but either A or B. but i would go with A
question 2: B-calvin cycle
question3: B-splitting carbon dioxide.
question 4: B-chlorophyll