Strongest acid among the following is

Options

A. `CH_(3)COOH`
B. `FCH_(2)COOH`
C. `F_(2)CHCOOH`
D. `F_(3)C-COOH`

Explanation

To determine the strongest acid among the given options, we need to analyze the structure of each carboxylic acid and the presence of electron-withdrawing groups that can stabilize the conjugate base formed after deprotonation.

### Step-by-Step Solution:

1. **Identify the Structure of Each Acid:**
- Option A: CH3C(=O)OH (Acetic Acid)
- Option B: FCH2C(=O)OH (Fluoroacetic Acid)
- Option C: F2CHC(=O)OH (Difluoroacetic Acid)
- Option D: F3C(=O)OH (Trifluoroacetic Acid)

2. **Understand the Concept of Acidity:**
- The acidity of a carboxylic acid is influenced by the stability of its conjugate base (the carboxylate ion formed after losing a proton).
- A more stable conjugate base corresponds to a stronger acid.

3. **Analyze the Electron-Withdrawing Groups:**
- Electron-withdrawing groups (EWGs) stabilize the negative charge on the conjugate base, making the acid stronger.
- The strength of the EWG effect increases with the number of electronegative atoms attached to the carbon adjacent to the carboxylic group.

4. **Evaluate Each Option:**
- **Option A (Acetic Acid)**: Contains a methyl group (CH3) which has a +I effect (electron-donating), making it a weaker acid.
- **Option B (Fluoroacetic Acid)**: Contains one fluorine atom, which has a -I effect, providing some stabilization to the conjugate base.
- **Option C (Difluoroacetic Acid)**: Contains two fluorine atoms, which increases the -I effect, making the conjugate base more stable than that of Fluoroacetic Acid.
- **Option D (Trifluoroacetic Acid)**: Contains three fluorine atoms, providing the strongest -I effect, leading to maximum stabilization of the conjugate base.

5. **Conclusion:**
- Based on the analysis, Trifluoroacetic Acid (Option D) has the strongest electron-withdrawing effect due to the presence of three fluorine atoms. This results in the greatest stabilization of its conjugate base, making it the strongest acid among the options provided.

### Final Answer:
The strongest acid among the given options is **Option D: Trifluoroacetic Acid (F3C(=O)OH)**.