( ( c -RRB- ) ( ( ( The image ) ( produced ( in ( a ( plane mirror ) ) ) ) ) ( ( is virtual ) . ) ) )
(ROOT (S (LST (LS c) (-RRB- -RRB-)) (NP (NP (DT The) (NN image)) (VP (VBN produced) (PP (IN in) (NP (DT a) (NN plane) (NN mirror))))) (VP (VBZ is) (ADJP (JJ virtual))) (. .)))
c) The image produced in a plane mirror is virtual.
(ROOT (S (NP (DT A) (NN plane) (NN mirror)) (VP (VP (VBZ has) (NP (DT a) (ADJP (JJ flat) (JJ reflective)) (NN surface))) (CC and) (VP (VBZ forms) (NP (RB only) (JJ virtual) (NNS images)))) (. .)))