`IUPAC` name of given compound is:
`H-undersetunderset(O)(||)(C)-CH_(2)-undersetunderset(CH_(3))(|)(CH)-C=N`

Options

A. `3`-Carbonitrile-`3`-methyl butanal
B. `3`-Formyl-`2`-methyl propane nitrile
C. `3`-Cyanobutanal
D. `2`-Methyl-`4`-oxobutane nitrile

Answer

To determine the IUPAC name of the given compound, we will follow a systematic approach. Let's break it down step by step:

### Step 1: Identify the Functional Groups
The compound contains:
- An aldehyde group (–CHO)
- A nitrile group (–C≡N)
- A ketone group (C=O)

### Step 2: Determine the Longest Carbon Chain
We need to find the longest continuous carbon chain that includes the highest priority functional groups. In this case, the nitrile group (–C≡N) takes precedence over the aldehyde group (–CHO).

### Step 3: Number the Carbon Chain
We will number the carbon chain starting from the end closest to the highest priority functional group (the nitrile group).

1. Start from the right where the nitrile group is located.
2. Number the carbons:
- C1: C≡N (nitrile)
- C2: Aldehyde (–CHO)
- C3: CH2
- C4: CH (with a methyl group attached)

### Step 4: Identify Substituents
From the structure:
- There is a methyl group (–CH3) on C4.
- The aldehyde group is on C2.
- The nitrile group is on C1.

### Step 5: Write the Name
Combine the names of the substituents and the main chain. The main chain is butane because there are four carbons.

- The aldehyde group is indicated by the suffix "al".
- The nitrile group is indicated by the suffix "nitrile".
- The methyl group is a substituent.

Putting it all together, we get:
- The correct IUPAC name is **2-methyl-4-oxo-butane-1-nitrile**.

### Final Answer
The IUPAC name of the compound is **2-methyl-4-oxo-butane-1-nitrile**.

---