An organic compound (A) `(C_(4)H_(10)O)` upon dehydrogenation gives a compound (B) which forms phenyl hydrazone with phenylhydrazine and both the compound (A) and (B) respond to iodoform test. Hence, the compound (A) is

Explanation

To solve the problem, we need to identify the organic compound (A) with the molecular formula \(C_4H_{10}O\) that upon dehydrogenation gives another compound (B). Both compounds respond to the iodoform test and compound B forms a phenyl hydrazone with phenylhydrazine.

### Step-by-Step Solution:

1. **Identify the Structure of Compound A**:
- The molecular formula \(C_4H_{10}O\) suggests that compound A could be an alcohol or an ether. However, since both compounds respond to the iodoform test, we can conclude that compound A must be a secondary alcohol or a methyl ketone.
- The possible structures for \(C_4H_{10}O\) include:
- Butan-1-ol (primary alcohol)
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