B

Step 1: Understanding fingerprints involves examining the unique patterns and ridges on the skin, which are often very small and intricate.
Step 2: A microscope is an optical instrument that provides magnification, allowing for detailed observation of small structures, such as fingerprints.
Step 3: Other options:
- Telescope: Used for observing distant objects, not suitable for close-up examination of fingerprints.
- Galilean telescope: A specific type of telescope, again not intended for detailed close examination.
- Concave lens: Although it could enlarge images, it is not specifically designed for detailed examination of fingerprints.
Therefore, the correct answer is: Microscope.