This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Histamine, 5-HT and PGs, Subject name: Pharmacology
True statement about fexofenadine is: 
Select and explain. 
A. It undergoes high first pass metabolism in liver, B. Terfenadine is an active metabolite of this drug, C. It does not block cardiac K+ channels, D. It has high affinity for central H1 receptors
C: It does not block cardiac K+ channels
Answer: C: It does not block cardiac K+ channels 
Explanation: Fexofenadine is an active metabolite of terfenadine. It lacks K+ channel blocking propey, therefore is devoid of arrhythmogenic potential. It is available as a separate second generation H1 blocking agent.