Answer
See the answer below.
Work Step by Step
a, b) Atom 1 is $sp^2$ hybridized because it makes a double bond, which makes angle A 120°.
Atoms 2 to 5 are $sp^3$ hybridized because they make single bonds only, which makes angles B, C and D approximately 109°.
c) The O-H bonds are the most polar because they have the biggest difference in electronegativity between the ligands.