Why Was the Davis Experiment Only Able to Detect One-Third

Why was the Davis experiment only able to detect one-third of the neutrinos originally predicted?

A) Most of the neutrinos were absorbed by Earth's atmosphere.
B) The neutrinos combined with other particles as they entered Earth's atmosphere.
C) The neutrinos distributed evenly among three different flavors while traveling to Earth.
D) The number of neutrinos was too great to be held in the tank that Davis designed.
E) The other two-thirds of neutrinos dissipated while traveling to Earth.