Answer the question on the basis of the information given below:
In the adjoining figure, I and II are circles with centres P and Q respectively. The two circles touch each other and have a common tangent that touches them at points R and S respectively. This common tangent meets the line P and Q at O. The diameters of I and II are in the ration $4:3.$ It is also known that the length of PO is $28$ cm.
What is the ration of the length of PQ to that of QO?
- $1:4$
- $1:3$
- $3:8$
- $3:4$