A low density beam of 8.0-eV electrons is incident on a potential barrier 15.0 eV in height and 0.80 nm in width. The fraction of the beam that is transmitted through the barrier is closest to:
A) 5.0 × 10-7
B) 1.7 × 10-9
C) 1.7 × 10-6
D) 3.3 × 10-5
E) 2.5 × 10-8