Chthamalus stellatus and Semibalanus balanoides do not coexist in the same tidal zones because

A) S. balanoides outcompetes C. stellatus in the lower tidal zone
B) C. stellatus outcompetes S. balanoides in the lower tidal zone
C) C. stellatus outcompetes S. balanoides in the upper tidal zone
D) S. balanoides outcompetes C. stellatus in the upper tidal zone
E) The two species require different resources