【单选题】

The passage is chiefly concerned with
A．(A) explaining the process by which the Earth and its oceans accreted

B．(B) reporting how recent research has arrived at a new explanation for the constitution of the Earth's oceans
C．(C) accounting for the chemical composition of the various ingredients of the Earth's oceans
D．(D) contrasting various competing hypotheses as to what the Earth's oceans consist of
E．(E) reporting inconsistencies with the result of new research into the composition of the Earth's oceans