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: Medicine
Which one of the following is the most common initial symtoms of byssinosis - 
Select and explain. 
A. Chest tightness, B. Wheezing, C. Cough, D. Haemoptysis
A: Chest tightness
Answer: A: Chest tightness 
Explanation: None