Final answer:
A reader will most likely encounter technical vocabulary in a computer instruction manual, due to its use of specialized terms to explain complex information.
Step-by-step explanation:
A reader is most likely to encounter technical vocabulary in a computer instruction manual. This type of text contains detailed procedural guides and uses specialized terminology to precisely convey complex information to the reader. Other options like a news website, a short story, and a vacation brochure are less likely to use technical language as they are usually aimed at a general audience and prioritize readability and engagement over technical detail.