HF is 4 units and GH is 2 units. Option C is the right choice.
As per given information,
△ DFE
△ GFH
Means △ DFE is same as of △ GFH.
So we can take the ration of the given sides of both the triangle.
DF = DG +GF
DF = 15 + 5 = 20 UNITS
Put the given values in that ratio
Separate it
and
8 = 4 GH
After dividing both side by 4 we get
GH = 2 units
4 HF = 12 + HF
3 HF = 12
After dividing both side by 3 we get
HF = 4 units
So, Option C is the right choice.