A normal $LM$ curve can be derived from the quantity equation if it is assumed that: a$.$ a higher interest rate reduces money demand and raises velocity. b$.$ a higher interest rate reduces both money demand and velocity. c$.$ velocity is constant. d$.$ the price level is constant. At the intersection of the IS and $LM$ curves: a$.$ actual expenditure is equal to planned expenditure. b$.$ real money supply is equal to real money demand. c$.$ the levels of $Y$ and $r$ satisfy both the goods market equilibrium condition and the money market equilibrium condition. all of the above.