See the answer below.
Work Step by Step
a) The carbon atom involved in the double bond makes a $\pi$ bond so it is $sp^2$ hybridized. The nitrogen is $sp^3$ hybridized. b) The two carbon atoms involved in double bonds make a $\pi$ bond so they are $sp^2$ hybridized. The other carbon is $sp^3$ hybridized. c) The leftmost carbon makes one and the rightmost, two $\pi$ bonds, so they are respectively $sp^2$ and $sp$ hybridized.