Final answer:
A trocar is the instrument used to penetrate soft tissue or bone, serving a similar purpose to an endoscope but without the latter's visualization capabilities. While trocars create a pathway for other instruments, endoscopes are designed to provide direct viewing and surgical assistance within the body.
Step-by-step explanation:
An instrument used for penetrating soft tissue or bone is known as a Trocar (option D). Tissue penetration for the purpose of internal examinations or procedures is often necessary in medical situations, and trocars are devices specifically designed for this task. By contrast, an Explorer is typically used in dentistry to examine tooth surfaces for decay, a Mirror is used to provide visibility in areas of the body or mouth that are difficult to see, and a Probe is used to measure the depth of periodontal pockets or investigate the surface of a tissue.
When considering devices like endoscopes, they are also designed to explore internal areas of the body. An endoscope is a flexible tube equipped with a light and camera that can be inserted into the body to observe internal organs and structures without the need for large incisions. Endoscopes can also channel light to illuminate internal parts, transmit reflected light for observation, and deliver surgical instruments to perform procedures such as biopsies or the removal of growths, similar to the trocar's function of penetrating tissues but with additional capabilities for visualization and minor surgeries.