<p style="">The correct answer is (B) evaluating.</p><p style="">This sentence is structured to require a gerund (-ing form of a verb) to function as a noun, indicating the action or process of something. The sentence is talking about "techniques" (the subject), followed by the preposition "for," which must be followed by a noun or a gerund acting as a noun, not a simple verb or past participle.</p><p style="">(A) "evaluate" is the base form of the verb and cannot follow the preposition "for."</p><p style="">(B) "evaluating" is the gerund form of the verb "evaluate," functioning as a noun, and correctly follows the preposition "for" to indicate the action that the techniques are designed for. This fits the sentence structure and maintains coherence in meaning.</p><p style="">(C) "evaluated" is the past participle of "evaluate" and doesn't fit here because it doesn't function as a noun.</p><p style="">(D) "evaluation" is a noun, and while it denotes the concept or result of "evaluating," it doesn't convey the ongoing or procedural action that the gerund "evaluating" does, which is more suitable in the context of discussing "techniques" for doing something.</p><p style="">So, the sentence should read: "There are a number of techniques for evaluating the usability of a product for intermediate or expert users, which can be quite time-consuming." This conveys that the techniques are used in the process of assessing usability, rather than the assessment as a one-time event or result.</p>