For greater accuracy, some micrometers have a vernier scale making it possible to read in increments of __________.

Correct Answer: Option B — ten thousands of an inch

Standard micrometers typically read to one-thousandth of an inch. The addition of a vernier scale, which divides the thousandths graduation into ten equal parts, allows for measurements to one-ten-thousandth of an inch. This level of precision is required for critical tolerances in high-speed rotating machinery and engine components.