I know you said you didn't care but ICAO DOC 8168, Definitions, gives:
"Standard instrument arrival (STAR). A designated instrument flight rule (IFR) arrival route linking a significant point, normally on an ATS route, with a point from which a published instrument approach procedure can be commenced."
So your book is not 100% correct by including the brackets. A small point I agree but even with that information you would answer (a). In the general case you can either ask the database provider or your ATO for clarification or check online. I would not say that this was actually debatable as VFR arrival procedures also exist and would fall under the definition given at (b).