Which of the following is the correct statement? 

CONCEPT:

Isomerism in Coordination Complexes

• Tetrahedral complexes have symmetrical geometry, and due to their symmetry, they cannot exhibit geometric isomerism. This means tetrahedral complexes can exist only in one form.
• Square planar complexes, on the other hand, can exhibit geometric isomerism. For example, in a complex of the type [MA₂B₂], there can be two isomers: cis (where the same ligands are adjacent) and trans (where the same ligands are opposite).

EXPLANATION:

• "Tetrahedral complex can exist only in one form" - This is correct because tetrahedral complexes are symmetrical and cannot form isomers.
• "Square planar complex can exist in two isomeric forms" - This is also correct because square planar complexes can exhibit cis and trans isomerism.
•  "Tetrahedral complex can exist only in one form and Square planar complex can exist in two isomeric forms" - This combines the correct statements from Options 1 and 2, making this the correct choice.
•  "None of these" - This is incorrect because Options 1 and 2 are valid statements.

Therefore, the correct answer is Option 3: "Tetrahedral complex can exist only in one form and Square planar complex can exist in two isomeric forms."