Question

which of these has the highest degree of precision when measuring the thickness of a spacer? vernier caliper tape measure ruler micrometer

Explanation:

A micrometer is designed to measure very small lengths with high precision. It can measure to a much finer degree than a vernier caliper, tape measure, or ruler. Tape measures and rulers have relatively large - scale markings and are less precise for small thicknesses. A vernier caliper is more precise than a tape measure or ruler but less precise than a micrometer for very small measurements like the thickness of a spacer.

Answer:

Micrometer