NB: This is a business question, not biology.
Answer:
SAC (Short-run Average Cost) and LAC (Long-run Average Cost)
The stronger argument regarding the SAC (Short-run Average Cost) curves and the LAC (Long-run Average Cost) curves is:
A. The draftsman since the lowest point on each SAC curve will have a horizontal tangent line which only occurs at the lowest point on the LAC. 
Explanation:
The costs of all factors of production become variable in the long run.  But in the short-run, some costs are variable, and some are fixed.  When the producer starts operating over the long run period, it can then operate without the constraints imposed by the presence of the fixed-cost factors. Therefore, in the long run, the average cost (LAC) is equal to the short-run average cost (SAC) because there is an unconstrained minimum average cost at all output levels.
 
        
             
        
        
        
The relationship between the two species is a symbiotic relationship. 
        
             
        
        
        
Answer:
It enters the atmosphere through both natural and human sources. Natural resources can be for instance volcanic eruptions, bacterial processes, evaporation from water, or decaying organisms. ... Sulfur dioxide may also react with water to produce sulfuric acid (H2SO4).
Explanation:
 
        
             
        
        
        
The parachutes are the subject of the study and different types, or brands, of them should be used.
        
             
        
        
        
Answer:
D: all of the above
Explanation:
Autotrophs have photosynthesis so they are like plants they make their food by photosynthesis they are base of the food chain because other animals eat it