Answer: Option (3) is the correct answer.
Explanation:
When a linear chain of carbon and hydrogen atoms is attached by single bonds only then it is known as alkane.
When a linear chain of carbon and hydrogen atoms contains a double bond then it is known as alkene.
When a linear chain of carbon and hydrogen atoms contains a triple bond then it is known as alkyne.
Therefore, in the given description there is a double bond between third and fourth carbon. Hence, the IUPAC name of given compound is 3-heptene.
