Which of the following does not belong to the main schools of linguistics

A．Marine sediments have allowed scientists to amass evidence tending to confirm that astronomical cycles drive the Earth's glacial cycles.
B．The ratio between two different isotopes of oxygen in seawater correlates closely with the size of the Earth's ice sheets.
C．Surprisingly, single-cell marine organisms provide a record of the Earth's ice ages.
D．The Earth's astronomical cycles have recently been revealed to have an unexpectedly large impact on the Earth's climat

A．water molecules containing oxygen-18 condense and fall as precipitation slightly sooner
than those containing oxygen-16
B．the ratio of oxygen-18 to oxygen-16 in water vapor evaporated from oceans if different from that of these isotopes in seawater
C．growing ice sheets tend to lose their oxygen-18 as the temperature of the oceans near them gradually decreases
D．less water vapor evaporates from oceans during glacial periods and therefore less oxygen-18 is removed from the seawater