Using GSS2006 Data, We Investigate the Relationship Between Education and Concern

Using GSS2006 data, we investigate the relationship between education and concern over global warming (concern is measured in a scale from 0=not concerned, up to 15=great concern) . We think that support for science (measured on a scale from 0=no support, up to 9=full support) could play a mediating role in this. We get the following arrows and betas for a path model (all betas are statistically significant) :
Beta for arrow from education to science support: +.25
Beta for arrow from education to global warming concern: +.10
Beta for arrow from science support to global warming concern: +.15
What percentage of the total effect is direct?

A) 10%
B) 20%
C) 37%
D) 71%