Ocean currents have an effect on the earth's climate. What evidence from the passage supports this conclusion?
A Some ocean currents, like the Gulf Stream, have a direct effect on the
climates of the countries they pass.
B The gradual increase of the earth's temperature has been a topic of much
debate.
С Cold water does not always stay at the bottom of the ocean.
D As water freezes in the North and South Poles, the water surrounding the
ice becomes saltier and colder.

I think it's A or C I'm not 100%

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."