Neutrino Detectors for Astronomical Purposes Are Built and Operated Deep

Neutrino detectors for astronomical purposes are built and operated deep underground to:

A) shield them against other high-energy radiation from space or from natural radioactivity.
B) reduce the effect of rotational speed produced by Earth's rotation, because the sensitive neutrino detection techniques are adversely affected by Doppler shifts.
C) utilize the gravitational focusing of neutrinos that occurs in Earth's core.
D) ensure that they are absolutely light-tight, because they depend on the detection of very faint flashes of light.