The compound in which carbon uses only its $sp^3$ hybrid orbitals for bond formation is

$(a)$ Discuss the concept of hybridization. What are its different types in a carbon atom.
$(b)$ What is the type of hybridization of carbon atoms marked with a star in the following structures:
$(a)$ $\overset{*}{C}H_2 = CH - C(=O)OH$
$(b)$ $CH_3 - \overset{*}{C}H_2 - OH$
$(c)$ $CH_3 - CH_2 - \overset{*}{C}H = O$
$(d)$ $\overset{*}{C}H_3 - CH = CH - CH_3$
$(e)$ $CH_3 - \overset{*}{C} \equiv CH$

Which of the following represents the given mode of hybridization $sp^2 - sp^2 - sp - sp$ from left to right?

The compounds containing $sp$-hybridised carbon atom are:
$(I)$ $H_3C-N(CH_3)-CHO$
$(II)$ Pyridine
$(III)$ $H_3C-CN$
$(IV)$ $H_2C=C=CH-CH_3$

What is the type of hybridisation of each carbon atom in the following compounds?
$(a)$ $CH_{3}Cl$
$(b)$ $(CH_{3})_{2}CO$
$(c)$ $CH_{3}CN$
$(d)$ $HCONH_{2}$
$(e)$ $CH_{3}CH=CHCN$

Which among the following possesses a $sp$ carbon in its structure?