A D

This sentence is comparing two “versions” of a product. The first blank requires a synonym of “version,” such as “iteration.” There’s a bit of a theme trap in “ingenuity,” which means innovation or creativity. An “implication” is either an insinuation or a consequence; neither makes sense in this context. The second blank describes a “version” that is contrasting with the “next iteration,” so that would logically be the previous one. “Current” works well here (and “obsolete” is too judgmental; it’s not outdated or out of production yet!). It might be true that the version is “practical,” but the given sentence doesn’t suggest this additional meaning; if anything, “refuse to purchase” disagrees with the idea of a practical version of the product.