Complementary cells occur in
A. Lenticels - The slightly raised spots present on the surface of dicot stem after secondary growth are called Lenticels. These are large sized aerating pores present in the cork tissue for gaseous exchange. The interior of the lenticel is filled with a loose mass of thin-walled rounded suberised cells called complementary cells.
B. Phloem – food conducting complex tissue
C. Endodermis of monocot stem – Endodermis is absent in monocot stem.
D. Exodermis – The outer suberised cells present in mature monocot root.
So, the correct option is ‘Lenticels’.