Hottest stars burn more brightly
        
             
        
        
        
He could have taken it to an area out of his workstation while telling his boss he had a phone call.
Or 
He could have been more polite on the phone.
        
             
        
        
        
"B. organisms that use the same resource" is destined to cause the most competition between those organisms, since resources are scarce and almost always limited. 
        
                    
             
        
        
        
I can already say it's not option 1 nor 4 as these go against everything science is. I'd say it's option 3 since it takes a bit and though yes they can be rejected, many scientists build off another individual studying the same material for a lead on where they should look. I hope this works for you and I'm not wrong. It's just that option 3 is most understandable in my mind with common sense of previous schooling.