Final answer:
Option D.
The mismatched rock type and environment from the options is sandstone in a low-energy, deep ocean environment, because sandstone usually forms in moderate to high-energy conditions.
Step-by-step explanation:
The student's question asks which of the listed rock types is not matched with the correct environment. Upon evaluating the given options against our knowledge of geologic processes and environments where different rock types form, we can determine the correct answer.
Conglomerate is typically found near mountain ranges and forms in high-energy environments from the cementation of larger, rounded clasts, indicating that option A is correctly matched.
Mudstone forms in low-energy environments, typically far from the source of the sediment, which makes option B accurate as well. Gneiss, a high-grade metamorphic rock, forms under conditions of high pressure and temperature, often deep within mountain roots, confirming that option C is correctly matched.
Limestone usually forms in warm, shallow marine environments where organisms with calcareous shells can accumulate, making option E a correct match.
However, sandstone typically forms in environments associated with a moderate to high energy level, such as river channels, beaches, or desert dunes rather than in the low energy conditions of the deep ocean. Hence, option D is not correctly matched to the environment listed.