SOMINE PLSSS ANSWER THIS ONE
Keep in mind that we're framing it based on what the first sentence says, which is "If the cost of a competing factor of production, such as a machine that also could do the job, rises".
So if the cost of getting a machine part, various parts, or the entire machine cost rises, then demand for the machine will go down. This will make employers seek out substitutes. In this case, those substitutes would be human labor. As employers demand for labor goes up, the wages will rise assuming the supply of workers is held constant. If the supply of workers increased, then you could argue the wages could go down. So that's why I'm assuming the supply is held in check.