I'd say C. an allergic reaction. Mainly because lots of people are allergic to many things and many people intend to have seasonal allergies cause by plants. Hope it helps!
        
                    
             
        
        
        
A cloud of gas, if large enough, begins to contract. The density and temperature increase, so that nuclear fusion can begin. This is when Hydrogen becomes Helium.When hydrogen is "burned", the contraction stops. At this time, the gas becomes a star
        
                    
             
        
        
        
Answer:
just buy ur teacher some gifts and tell ur mum died then maybe shell forgive you for not doing ur homework nd all 
 
        
                    
             
        
        
        
Digestive system, heart, lungs
        
                    
             
        
        
        
Answer:
Sleep apnea.
Explanation:
Sleep apnea:
Sleep apnea is considered as serious sleep disorder in which patient's breathing during sleep repeatedly stop and start along with snoring. 
So, here the scenario that Sarah's grandfather is suffering from sleep apnea because he takes nap on recliner and suddenly stop snoring and stop breathing and again resume the breathing along with snoring.