In the Keynesian framework, determination of an equilibrium interest rate also implies
(A) The rate that equates the supply of and the demand for bonds.
(B) The rate that equates the supply of money with the demand for money.
(C) The rate that equates the supply of money and demand for investment.
(D) The rate that equates supply of labour and demand for labour.
Choose the correct answer from the options given below:
A racing track is built around an elliptical ground whose equation is given by \[ 9x^2 + 16y^2 = 144 \] The width of the track is \(3\) m as shown. Based on the given information answer the following: 
(i) Express \(y\) as a function of \(x\) from the given equation of ellipse.
(ii) Integrate the function obtained in (i) with respect to \(x\).
(iii)(a) Find the area of the region enclosed within the elliptical ground excluding the track using integration.
OR
(iii)(b) Write the coordinates of the points \(P\) and \(Q\) where the outer edge of the track cuts \(x\)-axis and \(y\)-axis in first quadrant and find the area of triangle formed by points \(P,O,Q\).