Co-ordination complexes can show stereoisomerism square planar complexes of `Ma_(2)b_(2)` type can show geometrical isomerism but not optical & octahedral complexes of `Ma_(2)b_(2)C_(2), Ma_(3)b_(3) Mabcdef` etc show stereoisomerism, for e.g. `Mabcdef` have 15 geometrical isomers & all are optically active so it has 15 pairs of enantiomers thus in totaly it has 30 stereoisomers. (a,b,c,d etc. are monodentate lignads while `AB` is bidenatate ligand)
Which of the following can show geometrical as well as optical isomerism?

Options

A. `M(AB)_(3)`
B. `Mabcd` (tetrahedral)
C. `Ma_(3)b_(3)`
D. `Ma_(4)b_(2)`

Explanation

To solve the question regarding which coordination complexes can show both geometrical and optical isomerism, we will analyze the types of complexes mentioned in the question.

### Step-by-Step Solution:

1. **Understanding Coordination Complexes**:
- Coordination complexes consist of a central metal atom bonded to surrounding ligands. The arrangement of these ligands around the metal can lead to different types of isomerism.

2. **Identifying Types of Isomerism**:
- **Geometrical Isomerism**: This occurs when ligands can be arranged differently in space, leading to distinct isomers (e.g., cis and trans forms).
- **Optical Isomerism**: This occurs when a compound can exist in two forms that are mirror images of each other (enantiomers) and cannot be superimposed.

3. **Analyzing Square Planar Complexes (MA2B2)**:
- Square planar complexes of the type MA2B2 can exhibit geometrical isomerism (cis and trans forms) but do not show optical isomerism due to the presence of a plane of symmetry.

4. **Analyzing Octahedral Complexes**:
- Octahedral complexes of the type MA2B2C2 and MA3B3 can exhibit both geometrical and optical isomerism. For instance:
- MA2B2C2 can have geometrical isomers (cis and trans) and can also be optically active if there is no plane of symmetry.
- MA3B3 can have multiple arrangements, but typically, they may have a line of symmetry, which would prevent optical isomerism.

5. **Analyzing Tetrahedral Complexes (MABCDE)**:
- Tetrahedral complexes generally do not exhibit geometrical isomerism due to their symmetrical nature and the free rotation of ligands around the central metal ion.

6. **Conclusion**:
- Based on the above analysis, the coordination complex that can show both geometrical and optical isomerism is likely of the octahedral type (like MA2B2C2) that does not possess a plane of symmetry.

### Final Answer:
The coordination complex that can show both geometrical and optical isomerism is of the type **MA2B2C2**.