This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Skin
Parakeratosis is defined as: 
Select and explain. 
A. Retention of cytoplasmic contents in stratum corneum, B. Retention of nuclei in stratum corneum, C. Increased thickness in stratum corneum, D. Decreased thickness of stratum corneum
C: Increased thickness in stratum corneum
Answer: C: Increased thickness in stratum corneum 
Explanation: Increased thickness in stratum corneum