Arrange the carbonions,
`(CH_(3))_(3)overset(-)C, overset(-)C Cl_(3), (CH_(3))_(2) overset(-)CH, C_(6)H_(5)overset(-)CH_(2)` in order of their decreasing stability

Options

A. `(CH_(3))_(2)overset(-)CH gt overset(-)C Cl_(3) gt C_(6)H_(5)overset(-)CH_(2) gt (CH_(3))_(3)overset(-)C`
B. `overset(-)C Cl_(3) gt C_(6)H_(5)overset(-)CH_(2) gt (CH_(3))_(2)overset(-)CH gt (CH_(3))_(3)overset(-)C`
C. `(CH_(3))_(3) overset(-)C gt (CH_(3))_(2)overset(-)CHgt C_(6)H_(5)overset(-)CH_(2) gt overset(-)C Cl _(3)`
D. `C_(6)H_(5)overset(-)CH_(2) gt overset(-)C Cl_(3) gt (CH_(3))_(3) overset(-)C gt (CH_(3))_(2) overset(-)CH`

Answer

To determine the stability of the given carbanions, we need to analyze the effects of substituents on the carbon atom that carries the negative charge. The stability of carbanions is influenced by inductive effects and resonance.

### Step-by-Step Solution:

1. **Identify the Structures of the Carbanions**:
- (CH₃)₃C⁻: This is a tert-butyl carbanion where the negative charge is on a carbon atom bonded to three methyl groups.
- CCl₃⁻: This is a trichloro carbanion where the negative charge is on a carbon atom bonded to three chlorine atoms.
- (CH₃)₂CH⁻: This is an isopropyl carbanion where the negative charge is on a carbon atom bonded to two methyl groups and one hydrogen.
- C₆H₅CH₂⁻: This is a benzyl carbanion where the negative charge is on a carbon atom bonded to a benzene ring and a hydrogen atom.

2. **Analyze the Effects on Stability**:
- **(CH₃)₃C⁻**: The three methyl groups exert a +I (inductive) effect, which increases the electron density at the negatively charged carbon, making it less stable.
- **CCl₃⁻**: The three chlorine atoms exert a -I (inductive) effect, which decreases the electron density at the negatively charged carbon, making it more stable.
- **(CH₃)₂CH⁻**: The two methyl groups also exert a +I effect, which increases the electron density at the negatively charged carbon, but less so than in the case of (CH₃)₃C⁻.
- **C₆H₅CH₂⁻**: The negative charge can be delocalized through resonance with the benzene ring, significantly stabilizing the carbanion.

3. **Rank the Carbanions by Stability**:
- **Most Stable**: CCl₃⁻ (due to -I effect from Cl atoms)
- **Second Stable**: C₆H₅CH₂⁻ (due to resonance stabilization)
- **Third Stable**: (CH₃)₂CH⁻ (due to +I effect from two methyl groups)
- **Least Stable**: (CH₃)₃C⁻ (due to +I effect from three methyl groups)

### Final Order of Stability:
1. CCl₃⁻
2. C₆H₅CH₂⁻
3. (CH₃)₂CH⁻
4. (CH₃)₃C⁻