Give the structure of the Hexanal molecule.

The molecule has an aldehyde functional group. The term "hex" implies that the organic compound's longest potential carbon chain has six atoms.

In order to determine the structure of the chemical, let's begin by determining the functional group that is present in it.
We can see that the name Hexanal contains the -al suffix. This implies that an aldehyde functional group is present.
The word "hex" in the Hexanal structure denotes the presence of six carbon atoms.
We now need to determine where this aldehyde group will attach. By displaying the number of the aldehyde carbon in this instance, we are not provided a specific location. So in this instance, we'll assume that this is 1-Hexanal.
This indicates that the aldehyde group is connected to the alkyl chain's first carbon. Additionally, the carbon chain is free of any substituent groups.

We may state that there is a six carbon chain present in the molecule, with the aldehyde carbon being the first carbon of the chain since there are a total of six carbons in the compound and no substituent groups are present in the group.
Therefore, we may give the hexanal the following structure.

Hence, the correct answer is option C.