# Which of the following is an ether? How can you tell?

## $C {H}_{3} C O C {H}_{3}$ $C {H}_{3} C O O C {H}_{3}$ $C {H}_{3} O C {H}_{3}$ $C {H}_{3} C {H}_{2} O H$ $C {H}_{3} C O O H$

$C {H}_{3} O C {H}_{3}$
$C {H}_{3} C O C {H}_{3}$ is a ketone
$C {H}_{3} C O O C {H}_{3}$ is an ester
$C {H}_{3} C {H}_{2} O H$ is an alcohol
$C {H}_{3} C O O H$ is a carboxylic acid