Five membered rings come under which category of heterocycle classification on the basisof chemical behavior?

Can’t say about the five membered rings

Five membered rings come under which category of heterocycle classific

1.	Five membered rings come under which category of heterocycle classification on the basisof chemical behavior?
A.	-excessive heterocycle
B.	-deficient heterocycle
C.	-equivalent heterocycle
D.	Can’t say about the five membered rings
Answer» B. -deficient heterocycle