That's a hard one but I would go with A unwanted transpitation.  Hope that helped :)
        
             
        
        
        
Answer:
A. Deposition - sediment is set down in a new place
 
        
             
        
        
        
In the SI system of units, the standard unit of acceleration is 1 metre per second squared<span> (abbreviated as m/s2). Other units include the gal (sometimes known as a galileo, in either case with symbol Gal), which equals 1 centimetre per second squared, and the g (gn), equal to 9.80665 m/s2.</span>
        
             
        
        
        
<em>the following diagram explains it clearly:
</em>
 
        
        
        
That would be : adenine, thymine, guanine, and cytosine.