Is there an adjective expressing that a certain thing is to be chosen?

Question

I'm translating a literature list, and roughly translated, one of the entries reads "Any book of approximately 250 pages, dealing with the topic chosen for the argumentative essay" – but the word corresponding to "any" has a much stronger sense of 'chosen by the student'. If I were to rephrase it, I'd say "The student should choose any book of approximately 250 pages, dealing with..."

My question, then, is: is there a single adjective that I can use here, in this sense?

I've thought about "An optional book of...", but that seems to imply that the student can choose not to use a book, rather than that they are supposed to use a book, but that they may choose any book. I've also thought about "A choice book of..." but I have a feeling that that means 'well-chosen' rather than 'possible to choose'?

As always, I'd be immensely grateful for any help I can get :)

Answer 1

I would use "a book of the student's choice".

Of X's choice (often of your choice, but equally valid as of my choice, of her choice, of the President's choice, etc.) is an idiom that means "that X chooses from all of the available options". This implies that the student can choose any book, but unlike optional, means that the choice itself is mandatory.

Answer 2

Actually what you ask in your question is different from what you ask in the title. The answer to the title might include "selectable", but of course this word cannot be used the way you want, because what you want is not an adjective for "able to be chosen" but rather for "that is to be chosen". One option (already given by Stangdon) is "any book of your choice". Another option is simply "any chosen book", because in your context (i.e. it appears as one entry in a list) it implies that the one who picks from the list is to choose the book if he/she picks that entry.