Which one of the following will be able to show cis-trans isomerism ?

Options

A. `Ma_(3)b`
B. `M(A A)_(2)`
C. `M(AB)(CD)`
D. `Ma_(4)`

Explanation

To determine which of the given coordination compounds can show cis-trans isomerism, we will analyze each option step by step.

### Step 1: Understand the concept of cis-trans isomerism
Cis-trans isomerism occurs in coordination compounds when there are different ligands attached to the central metal ion, and the spatial arrangement of these ligands can differ. Typically, this is observed in square planar and octahedral complexes.

### Step 2: Analyze the options
1. **Option A: MA3B**
- This complex has three identical ligands (A) and one different ligand (B).
- In this case, regardless of how the ligands are arranged, the position of B relative to A will not create distinct isomers because all A ligands are equivalent.
- **Conclusion**: Does not show cis-trans isomerism.

2. **Option B: MA2A2**
- This complex has two identical bidentate ligands (A) and two identical ligands (A).
- Since all A ligands are identical, rearranging them does not yield different spatial arrangements.
- **Conclusion**: Does not show cis-trans isomerism.

3. **Option C: MABCD**
- This complex has two different bidentate ligands (AB) and (CD).
- The arrangement of these ligands can lead to different spatial configurations.
- For example, if we have AB on one side and CD on the other, we can interchange them to create different isomers (cis and trans).
- **Conclusion**: Can show cis-trans isomerism.

4. **Option D: MA4**
- This complex has four identical ligands (A).
- Similar to option A, since all ligands are identical, rearranging them does not create distinct isomers.
- **Conclusion**: Does not show cis-trans isomerism.

### Step 3: Final Conclusion
Based on the analysis of each option, the only compound that can show cis-trans isomerism is **Option C: MABCD**.

### Summary of Steps:
1. Understand cis-trans isomerism.
2. Analyze each option for the potential to create different spatial arrangements.
3. Conclude that only MABCD can show cis-trans isomerism.