A student while studying the anatomy of leaves of four specimens (P - S), observed the following characters:

P.  Reticulate venation and no bundle sheath.

Q. Parallel venation and bundle sheath having chloroplasts.

R.  Reticulate venation and bundle sheath having chloroplasts.

S.  Parallel venation and bundle sheath without chloroplasts.

Recognize the type of plants.

a.  P and R are C4 dicots, while Q and S are C4 monocots.

b. P and R are C3 dicots, while Q and S are C3 monocots.

c. P and S are C3 dicot and monocot, respectively, while Q and R are C4 monocot and dicot, respectively.

d.  P and S are C4 dicot and monocot, respectively, whereas Q and R are C3 monocot and dicot, respectively.