Answer:
D= 109.5 degrees, 109.5 degrees, 120 degrees
Explanation:
The bond angle observed for any bond between two chemical species depends on the hybridization of the atoms.
However, for organic compounds, single bonds normally involve sp3 hybridized atoms with a bond angle of 109.5 degrees such as in the positions marked a and b.
However, a double bond is made of atoms in sp2 hybridized state with a bond angle of 120 degrees such as in c.