Suppose that in $2018$ the income of all buyers of real estate services increased. Assume that the services of real estate agents and housing are both normal goods. Holding all else equal, what happens in the market for real estate agents?Select one:O a$.$ equilibrium price increases and equilibrium quantity increases b$.$ equilibrium price decreases and equilibrium quantity increases c$.$ equilibrium price increases and equilibrium quantity decreasesO d$.$ equilibrium price decreases and equilibrium quantity decreases