# Increasing order of stability among the three main conformation (ie eclipse, anti, gauche) of 2- fluoroethanol is

$(a)\;Eclipse,gauche,anti \\ (b)\;Gauche,eclipse,anti \\(c)\; Eclipse,anti,gauche \\ (d)\;Anti,gauche,eclipse$

The anticonformation is most stable in which F and OH groups are far apart as possible and minimum repulsion between two groups occurs.
In fully eclipsed conformation F and OH groups are so close that the steric strain is maximum .
Hence this conformation is most unstable.
The order of stability of these conformations is anti > gauche > partially eclipsed > fully eclipsed.
Hence a is the correct answer.