Which of the following best describes manual dexterity?

Manual dexterity refers to the ability to skillfully use one's hands and fingers to manipulate tools, instruments, or objects with precision and control. This skill is crucial in various fields, including medicine, craftsmanship, and the arts, where fine motor skills play a significant role in the quality of work produced.

The focus on accurately using tools and instruments encompasses a range of activities that require coordination, timing, and spatial awareness — all hallmarks of manual dexterity. This makes the second option the correct choice.

In contrast, the other options highlight different skills not related to physical manipulation. For instance, singing and vocal performance relate to auditory and vocal skills, while mental calculation and reasoning deal with cognitive abilities. Proficiency in theoretical knowledge of music also pertains to understanding music theory rather than the physical skill of manipulating instruments. Thus, the emphasis on the ability to use tools and instruments accurately aligns perfectly with the definition of manual dexterity.