The IUPAC name of the following compound
1
Cyclohexane-3, 4, 5, 6-tetracarboxylic acid 5, 6anhydride
2
Cyclohexane-1, 2, 3, 4-tetracarboxylic acid 1, 2anhydride
3
Cyclohexane-1, 2, 3, 4-tetracarboxylic acid 3, 4anhydride
4
Cyclohexane-2, 3, 4, 5-tetracarboxylic acid 2, 3anhydride