Here's a problem to solve: Evidence of extensive glaciation has been suggested as an explanation for extinctions at the end of the Permian period. Such glaciation could have disrupted ocean ecosystems by producing which effect?

Among the 4 following options, which is the correct answer?

- A: steep drop in ocean salinity and density
 
- B: steep drop in ocean volume and area
 
- C: increased exposure of oceans to ultraviolet radiation
 
- D: increased exposure of tsunamis to ocean life
 