Last Chance CLEP -- Natural Science or Biology?

[SUOfftheBooks]

I last took biology in the 10th grade -- in 1982 -- and I passed that by the grace of a lecherous teacher, mini skirts and French cut t-shirts.

I took a physical science course in college -- in 1984 -- and I did well, but obviously, I remember none of that after 30 years.

I am in my final semester, and I need to CLEP a science. My abstract math skills are week, so it's down to Bio or Natural Science. My plan is to take one of the tests in 2 weeks, and if I fail it, to study for another 1-2 weeks and take the other. I figure the last safe day I can take a test to get the results to the registrar in time to graduate is on/about 4/15 or 4/16.

Considering that I am starting with virtually no (remembered) knowledge of any of these subjects, which test would you attempt first?

Thanks!