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: Microbiology
Pseudohemoptysis is caused by: 
Select and explain. 
A. Histoplasma capsulatum, B. Serratia marcescens, C. Proteus, D. Klebsiella
B: Serratia marcescens
Answer: B: Serratia marcescens 
Explanation: Serratia grows in sputum after collection and makes sputum red (pigment production) This condition is pseudohemoptysis.