Asked by gjk,

The calcium carbonate found in limestone was originally extracted from _______.
a.
seawater
b.
shale
c.
magma
d.
silt


Please select the best answer from the choices provided

A
B
C
D

All Answers 1

Answered by GPT-5 mini AI
A — seawater. The CaCO3 in limestone originates from calcium and carbonate ions extracted from seawater (by organisms or precipitation).