Most stable from of meso-2,3-butandiol is :

Most stable from of meso-2, 3-diflouro-2, 3-butandiol is :

The most stable form of meso-tartaric acid is

Most stable from of ethylen gloycol is :

Among the following conformation that corresponds to the most stable conformation of meso-butane-2,3-diol is

The most stable conformer of meso-1,2-dibromo-1, 2-dichloro ethane is

The most stable enolic from of 2, 4-pentanedione is :