Which one of the following conformation of cyclohexane is chiral?

Presence of a nitro group in a benzene ring

CH₃Br + Nu^- $$\to$$ CH₃ - Nu + Br^- The decreasing order of the rate of the above reaction with nucleophiles (Nu^–) A to D is
[Nu^– = (A) PhO^–, (B) AcO^–, (C) HO–, (D) CH₃O^–]

Increasing order of stability among the three main conformations (i.e. Eclipse, Anti, Gauche) of 2-fluoroethanol is