A Particle of Kinetic Energy E₀ Traveling in a Region

A particle of kinetic energy E₀ traveling in a region in which the potential energy is zero is then incident on a potential barrier of height U₀.What is the ratio of E₀/U₀ so that the reflection co-efficient is 75%? (Assume E₀ is much less than the rest mass energy of the particle.)

A) 1.250
B) 0.7500
C) 1.778
D) 1.005
E) 1.063