The linear shape of C2H2 is due to
sp2 hybridization of carbon and pπ−pπ bond.
sp hybridization of carbon and pπ−pπ bond.
sp3 hybridization of carbon.
All the above.
[Step 1]:
H−C(sp)≡C(sp)−H
[Step 2]two carbon atoms are sp hybridization and oriented linearly with 180° bond angle.