The reaction
`CH_(3) CH = CH_(2) underset(H^(+))overset(CO + H_(2)O)(rarr) CH_(3) - underset("COOH")underset(|)(CH) - CH_(3)` is known as

Options

A. Wurtz reactions
B. Koch reaction
C. Clemmensen's reduction
D. Kolbe's reaction

Explanation

To solve the question regarding the reaction of the alkene `CH3CH=CH2` with CO and H2O in the presence of an acid, we need to identify the type of reaction that occurs.

### Step-by-Step Solution:

1. **Identify the Reactants**: The reactant is an alkene, specifically `CH3CH=CH2`, which is propene. The other reactants are carbon monoxide (CO) and water (H2O), with the presence of an acid (H+).

2. **Understand the Reaction Type**: The reaction involves the addition of CO and H2O across the double bond of the alkene. This is characteristic of a reaction that forms a carboxylic acid.

3. **Mechanism of the Reaction**:
- The alkene undergoes protonation in the presence of acid, forming a carbocation.
- The carbocation then reacts with CO, leading to the formation of a carbonyl compound.
- Water then adds to the carbonyl compound, followed by deprotonation to yield a carboxylic acid.

4. **Identify the Product**: The product formed is `CH3-C(COOH)-CH3`, which is a tertiary carboxylic acid.

5. **Name the Reaction**: This reaction is known as the **Koch reaction** (or Koch's reaction), which involves the synthesis of tertiary carboxylic acids from alkenes in the presence of CO and water.

### Final Answer:
The reaction is known as the **Koch reaction**.

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