The equation $C=100+0,9Y,$ where $C$ is consumption and $Y$ is disposable income, tells us that $...$

Select one:

a$.$ households will consume R$100,$ if their disposable income is zero and will consume $0,9$ of any increase in disposable income they receive.

b$.$ households earn R$100$ and spend three quarters of their income.

c$.$ households will consume $0,10$ of whatever level of disposable income they receive.

d$.$ households will save R$75,$ if their disposable income is zero and will consume $0,9$ of any increase in disposable income they receive.