With reference to your answer in (a), comment on the suggestion that Mars could be
capable of supporting life.
Observation that (radiation) flux is about half that on the Earth OR Earth
has about double the (radiation) flux of Mars (ecf answer to (a))
Sensible comment that makes reference to energy/intensity/number of
OR sensible comparison with polar or deep sea regions on the Earth
OR reference to a thinner atmosphere (allowing a greater fraction of
photons get through to surface)