b) Basal insulin
What are the main advantages of analogue basal insulin over rDNA human basal insulin?
Human basal insulin is isophane (human insulin mixed with protamine).
Pharmacokinetic profile of isophane: broad, rounded peak of activity, with a total duration of roughly 12 hours. In order to provide 24 hour basal coverage it would need to be injected twice a day.
Long acting basal insulin: Long acting analogues (glargine, detemir and degludec) produce much flatter insulin levels (peak-less) which mimics normal basal insulin levels more closely. They also only require once a day injection (detemir may require twice a day.
Isophane has more of a peak profile than the long acting analogues, so care is required with regard to hypoglycaemia.
I am providing a more extended answer for your reference, but for the exam the main points that should be covered are the frequency of dosing due to the duration of action, and flatter insulin level profiles of the analogues which better mimic basal insulin.