The species in which the cantral atom uses `sp^(2)` hybrid orbital in its bonding is:

Options

A. `PH_(3)`
B. `AsH_(3)`
C. `NH_(3)`
D. `CH_(3)^(+)`

Answer

To determine which species has a central atom that uses `sp²` hybrid orbitals in its bonding, we will analyze each option given in the question.

### Step-by-Step Solution:

1. **Analyze PS₃ (Phosphorus Trisulfide)**:
- The structure of PS₃ consists of a phosphorus atom bonded to three sulfur atoms and has one lone pair of electrons.
- The phosphorus atom forms three sigma bonds with sulfur and has one lone pair, which indicates that it is `sp³` hybridized (4 regions of electron density: 3 bonds + 1 lone pair).

2. **Analyze AsH₃ (Arsenic Trisulfide)**:
- The structure of AsH₃ consists of an arsenic atom bonded to three hydrogen atoms and has one lone pair of electrons.
- Similar to phosphorus, arsenic forms three sigma bonds and has one lone pair, indicating that it is also `sp³` hybridized.

3. **Analyze NH₃ (Ammonia)**:
- The structure of NH₃ consists of a nitrogen atom bonded to three hydrogen atoms and has one lone pair of electrons.
- Nitrogen also forms three sigma bonds and has one lone pair, which means it is `sp³` hybridized.

4. **Analyze CH₃⁺ (Methyl Cation)**:
- The structure of CH₃⁺ consists of a carbon atom bonded to three hydrogen atoms and has no lone pairs of electrons.
- Carbon forms three sigma bonds and has no lone pairs, indicating that it is `sp²` hybridized (3 regions of electron density: 3 bonds).

### Conclusion:
The species in which the central atom uses `sp²` hybrid orbitals in its bonding is **CH₃⁺ (Methyl Cation)**. Therefore, the correct answer is the fourth option.