The correct answer is: A. upward to the right from the origin.
A luxury good is a good for which demand increases as income increases. This is because as people become wealthier, they are able to afford more luxury goods. The income-demand curve for a luxury good will therefore slope upward to the right from the origin.
Option B is incorrect because a vertical income-demand curve would indicate that demand for the good is not affected by income. This is not the case for a luxury good, as demand for a luxury good will increase as income increases.
Option C is incorrect because an upward-sloping income-demand curve that only starts beyond a certain level of income would indicate that demand for the good is not affected by income until a certain level of income is reached. This is not the case for a luxury good, as demand for a luxury good will increase as income increases, regardless of the level of income.
Option D is incorrect because a horizontal income-demand curve would indicate that demand for the good is perfectly inelastic with respect to income. This is not the case for a luxury good, as demand for a luxury good will increase as income increases.