Solutional caves are formed in the earth when a soft rock, usually limestone, is eroded by rainwater that has mixed with soils and carbon dioxide to form carbonic acid. Troglotopia Cave and the surrounding earth contain low amounts of soft rock, so it is not a solutional cave.
For purposes of evaluating the argument it would be most useful to establish which of the following?
【选项】
Whether rainwater that mixed with soils and atmosphere ever forms an acid other than carbonic acid
选项是否正确？