Which of the following matches is correct? A. Pantene: CH3 – CH2 – CH – CH = CH2 B. Butene: CH3 – CH2 – CH = CH2 C. Ethene: CH2 = CH3 D. Propene: CH3 – CH2 = CH2

The correct answer is $\boxed{\text{B}}$.

Pantene is a hydrocarbon with the molecular formula $C_{10}H_{20}$. It is a straight-chain alkane with 10 carbon atoms. The structural formula of pentene is shown below:

$$\ce{CH3-CH2-CH2-CH2-CH=CH2}$$

Butene is a hydrocarbon with the molecular formula $C_4H_8$. It is an alkene with 4 carbon atoms and one double bond. The structural formula of butene is shown below:

$$\ce{CH3-CH2-CH=CH2}$$

Ethene is a hydrocarbon with the molecular formula $C_2H_4$. It is an alkene with 2 carbon atoms and one double bond. The structural formula of ethene is shown below:

$$\ce{CH2=CH2}$$

Propene is a hydrocarbon with the molecular formula $C_3H_6$. It is an alkene with 3 carbon atoms and one double bond. The structural formula of propene is shown below:

$$\ce{CH3-CH=CH2}$$

Therefore, the only option that matches the structural formula of pentene is $\boxed{\text{B}}$.