As a result of a supernova explosion, every human being on Earth was bombarded on February 23, 1987, by about 100 billion neutrinos; fortunately, neutrinos are harmless elementary particles that are produced in nuclear reactions and that interact very weakly with matter.
(A) neutrinos are harmless elementary particles that are produced in nuclear reactions and that
(B) neutrinos, which are harmless, are elementary particles produced in nuclear reactions and which
(C) neutrinos are harmless elementary particles produced in nuclear reactions and which
(D) these harmless elementary particles are produced in nuclear reactions, and neutrinos
(E) these elementary particles, harmless products of nuclear reactions, are neutrinos that