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: Pharmacology
Treatment of choice in solar keratosis is : 
Select and explain. 
A. Methotrexate, B. Topical 5 FU, C. Topical mechlorethamine, D. Topical steroids
B: Topical 5 FU
Answer: B: Topical 5 FU 
Explanation: Solar (actinic) keratosis is treated by application of liquid nitrogen. The alternative is 5-FU. Imiquimod cream can also be used.