Answer:
Option (C) 
Explanation: 
Sedimentary rocks are formed due to the compaction and lithification sediments. For example, mudstone, sandstone, and shale. 
Metamorphic rocks are those rocks that are formed when a sedimentary/igneous/other metamorphic rocks undergo changes in the pressure and the temperature conditions. Temperature and pressure are the main factors here. For example, slate, phyllite, schist, and gneiss. 
Mudstone is a sedimentary rock that can convert into a fine-grained and foliated metamorphic rock called slate due to the increase in the temperature and pressure. 
Hence, the correct answer is option (C).