Which of the following structures represents the lowest-energy from (1S, 2S 4R)-trimethyl-cyclohexane?

Which of the following structures represents the lowest-energy form of (1S, 2S, 4R)-trimethyl -cyclohexane ?

Which one of the following isomeric structures has the lowest energy ?

Which of the following schematic structures represent(s) cation(s)?

Which of the following represent(s) bidentate ligand(s)?

Which of the following represent(s) bidentate ligand(s)?