Final answer:
The argument suggests that the trend of increasing tablet computer sales will reverse, but this can be weakened if other factors affecting tablet sales are identified.
Step-by-step explanation:
The argument suggests that the trend of increasing tablet computer sales will reverse in the near future because the number of people in the age group of 18 to 25 is expected to decline steadily over the next 15 years. To weaken this argument, we need to provide evidence that tablet computer sales are not solely dependent on the 18 to 25 age group. Option C, which states that sales of tablet computers to small businesses have declined over the past 2 years, is the most relevant because it suggests that there are other factors affecting tablet computer sales besides the age group of 18 to 25. This weakens the argument that the decline in the 18 to 25 age group will lead to a reversal in tablet computer sales.