Final answer:
The word "give way" most closely matches the meaning of "weaken," as it indicates something collapsing or failing to hold, analogous to weakening.
Step-by-step explanation:
The question asks which of the following words matches the word "weaken": a) give in, b) relent, c) acquiesce, d) give way. To answer this, we need to understand the meaning of "weaken" and how it compares to the other word choices. Weaken means to make or become weaker, in terms of physical strength, power, or effectiveness. Among the given options, "give way" is the phrase that most closely matches the definition of "weaken."
While "give in," "relent," and "acquiesce" all signify a form of yielding or surrendering, often in terms of a position or argument, "give way" indicates something collapsing or failing to hold, which can be seen as a form of weakening.