According to MOT, two atomic orbitals overlap resulting in the formation of molecular orbital formed. Number of atomic orbitals overlapping together is equal to the molecule orbital formed. The two atomic orbital thus formed by LCAO (linear combination of atomic orbital) in the phase or in the different phase are known as bonding and antibonding molecular orbitals respectively. The energy of bonding molecular orbital is lower than that of the pure atomic orbitals by an amount `Delta`. This known as the stabilization energy. The enerby of antibonding molecular orbital in increased by `Delta'` (destabilisation energy).
Q. which of the following combination of orbitals is corrects?

Options

A.
B.
C.
D.

Explanation

To solve the question regarding the correct combination of orbitals based on Molecular Orbital Theory (MOT), we will analyze each option provided and determine whether the interactions lead to constructive or destructive interference.

### Step-by-Step Solution:

1. **Understanding Orbital Interactions**:
- When two atomic orbitals overlap, they can either be in the same phase (constructive interference) or in opposite phases (destructive interference).
- Constructive interference occurs when lobes of similar phase overlap, resulting in increased electron density, which leads to the formation of a bonding molecular orbital.
- Destructive interference occurs when lobes of opposite phase overlap, resulting in decreased electron density, leading to the formation of an antibonding molecular orbital.

2. **Analyzing Each Option**:
- **Option A**: This option shows a negative phase interacting with a positive phase. This indicates destructive interference, which means the electron density should decrease. However, if the electron density is increasing, this option is incorrect.

- **Option B**: Here, two negative phases are interacting. This indicates constructive interference, which means the electron density should increase. If the electron density is actually decreasing, this option is also incorrect.

- **Option C**: In this option, a negative phase interacts with a positive phase, indicating destructive interference. If the electron density is indeed decreasing, this option is correct.

- **Option D**: This option shows a negative sign between the lobes. If we assume the signs are reversed, we have a positive phase interacting with a negative phase, indicating destructive interference. If the electron density is increasing, this option is incorrect.

3. **Conclusion**:
- After analyzing all options, we find that **Option C** is the correct combination of orbitals where the negative phase interacts with the positive phase, leading to destructive interference and a decrease in electron density.

### Final Answer:
The correct combination of orbitals is **Option C**.