Detailed Instructions: In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
Q: Which of the following is not a computer vendor: Dell, Apple, or ThinkPad?, Context: In the shrinking PC industry, Dell continued to lose market share, as it dropped below Lenovo in 2011 to fall to number three in the world. Dell and fellow American contemporary Hewlett Packard came under pressure from Asian PC manufacturers Lenovo, Asus, and Acer, all of which had lower production costs and willing to accept lower profit margins. In addition, while the Asian PC vendors had been improving their quality and design, for instance Lenovo's ThinkPad series was winning corporate customers away from Dell's laptops, Dell's customer service and reputation had been slipping. Dell remained the second-most profitable PC vendor, as it took 13 percent of operating profits in the PC industry during Q4 2012, behind Apple Inc.'s Macintosh that took 45 percent, seven percent at Hewlett Packard, six percent at Lenovo and Asus, and one percent for Acer.
A:
ThinkPad