Final answer:
A negative reproduction of the patient's dental arch is referred to as an impression, which later can be used to create a positive cast of the dental arch.
Step-by-step explanation:
A negative reproduction of the patient's dental arch is referred to as a C) impression. In dentistry, the process involves creating a negative form of the teeth and surrounding structures. This is achieved by having the patient bite into a soft material that hardens to create a negative mold. Once the impression is taken, it can be used to make a positive reproduction or cast of the dental arch, which represents the shape and arrangement of the patient's teeth. This is analogous to how in paleontology, an organism leaves behind an impression in the sediment, and if this impression fills with new sediment, it forms a cast.