The renewable energy companies in competition for funding all had compelling ideas, but despite the (i)___________nature of the solar panel firm and its research, it bested the more inveterate competitors in attendance...

The solar panel firm bested the more established competitors despite its ___. So the blank must suggest some weakness of solar panel farms, and has to do with something "less established". Only inchoate (something that is in early-stage) echoes the same meaning, others are irrelevant. Answer B.

...(ii)___________the lion’s share of the acclaim at the festival.

So despite its weakness, the solar firms must have achieved a lot of success. Only "garnering" the lion’s share of the acclaim makes sense in this scenario. So answer F.