You need to do something like that your self so sorry can help.
Mass of solute ( m1 ) = 50.0 g
mass of solvent ( m2 ) = 150.0 g
Therefore:
m/m = ( m1 / m1 + m2 )
m/m = ( 50.0 / 50.0 + 150.0 )
m/m = ( 50.0 / 200 )
m/m = 0.25
I think its C: due to mixing and oceanic.....
The answer which would have been a major difference in the ocean basins is the following one:
<span>B. Mid-ocean ridges would have been chains of mountains.
Given that the waters were lower in the past, those ridges would no longer be just mid-ocean ridges, but complete mountains due to the low levels of water around them.</span>