Which of the Following Accurately Describes 18O/16O Ratios of the World's

Which of the following accurately describes 18O/16O ratios of the world's oceans?

A) A higher ratio of oceanic 16O to 18O,the colder the temperatures because 18O will have been mostly evaporated from the oceans.
B) Because 18O evaporates more readily than 16O,the oceans have a higher relative abundance of 16O during warm periods and a more balanced ration when evaporation is less.
C) Neither the 16O nor 18O isotopes are common in water,so when either is present,it shows a disequilibrium in normal climatic conditions.
D) During periods of colder temperatures,16O is locked up in snow and ice and 18O concentrations are highest in the oceans.
E) The 16O/18O ratio is low during colder temperatures because temperatures are too low for evaporation to be effective and both isotopes remain in the ocean.