Which is a relevant and measurable research question aimed at understanding the impact of marketing spend on the demand for the wearable fitness tracker?

A relevant, measurable research question should connect marketing spend with demand and identify something that can be measured. Choice B asks about monthly marketing spending and sales of the tracker, so their relationship can be examined using data. The other choices ask about product variety, update timing, or buyers’ reasons rather than the impact of marketing spend on demand.

AI-written and checked against the verified answer.