The correct option is A ethoxyethane
The given compound is an ether (R−O−R′). The ethers are named as alkoxyalkane. The smaller alkyl group attached to oxygen atom becomes the alkoxy substituent and the larger alkyl group is written as alkane. In this case, since ethyl group is present at either sides of the oxygen atom, the IUPAC name of the compound is ethoxyethane.