(S (S (S (BASENP (PRP It)) (VP (VBZ is) (VP (VBN caused) (PP (IN by) (BASENP (JJ obstructed) (NNS arteries)))))) (COMMA ,) (SBAR (WHNP (WDT which)) (S (VP (VP (VBZ causes) (BASENP (NN heart) (NN pain))) (PP (IN in) (NP (BASENP (DT a) (NN person) (POS 's)) (NN body))))))) (PERIOD .))