If current changes in ocean temperature and pH caused a mass extinction of today's reefbuilding organisms,

Question

A. we would see an unprecedented mass
extinction, unlike anything the earth has
experienced in the past.
B. we would see one more in a series of
mass extinctions that have wiped out reefs at
least 3 times since the first reefs appeared
over 500 million years ago.
C. we would see one more in a series of
mass extinctions that have wiped out reefs at
regular intervals – roughly every 10 million
years since the first reefs were formed over
500 million years ago.
D. we would see the second great mass
extinction of reefs; the only previous such
extinction took place at the end of the
Permian.
E. none of these

Answer 1

B