Life jackets are available here ________ request.
Show answer & explanation
Correct answer: D
Explanation
Fixed Phrase: The expression "on request" is a standard idiomatic phrase in English. It means that something will be provided or done if someone asks for it.
In professional or instructional settings (like on a plane or a boat), it indicates that while the items (life jackets) aren't currently distributed to everyone, they are ready to be given to anyone who asks for one.
The most appropriate word that fits in the blank is ‘on’.
The complete sentence is:
"Life jackets are available here on request."