Explanation:

CFSE stands for Crystal Field Stabilization Energy, which is the energy difference between the two states of a metal ion in a complex. The CFSE value depends on the number of unpaired electrons in the d-orbitals of the metal ion, as well as the geometry of the complex.

The CFSE for d3 metal ions (V2, Cr3, Mo3) decreases in the following order: Mo3 > Cr3 > V2. This means that Mo3 has the highest CFSE value, while V2 has the lowest CFSE value.

The reason for this trend is as follows:

1. Number of unpaired electrons: The CFSE value is directly proportional to the number of unpaired electrons in the d-orbitals of the metal ion. Among the three metal ions, V2 has the least number of unpaired electrons (only one), while Mo3 has the most number of unpaired electrons (three).

2. Ligand field strength: The CFSE value is also influenced by the strength of the ligand field around the metal ion. A stronger ligand field will cause the d-orbitals to split further apart, resulting in a larger energy difference between the two states. Among the three metal ions, Mo3 forms the strongest ligand field due to its larger size and greater charge density, while V2 forms the weakest ligand field.

3. Geometry of the complex: The CFSE value is also affected by the geometry of the complex. In general, tetrahedral complexes have a smaller CFSE value than octahedral complexes. Among the three metal ions, V2 and Mo3 generally form octahedral complexes, while Cr3 can form both octahedral and tetrahedral complexes. However, this factor is less significant than the first two factors.

Based on these factors, it can be concluded that Mo3 has the highest CFSE value, followed by Cr3 and V2. Therefore, the correct order is Mo3 > Cr3 > V2, which corresponds to option C.