Assume That a New Study Suggests the Corpus Callosum May

Assume that a new study suggests the corpus callosum may cause unipolar depression by moving messages too slowly from one cerebral hemisphere to the other. This study would be:

A) very unusual; previous studies have most strongly connected other brain areas to depression.
B) one of a kind; previous studies do not connect specific brain areas to depression.
C) unusual; only a few previous studies connect this brain area to depression.
D) expected; many previous studies connect this brain area to depression. This study is a replication.