Answer: d. it is impossible, currently, for an architect to supply his or her services at low cost to every customer
Explanation:
Actors and Athletes are able to offer their services to people around the world at very low cost with their service being to entertain.
It is not very expensive to go to the cinemas or buy a Blu-ray disc to watch a movie and with the explosion of subscription based movie streaming platforms such as Netflix, watching actions is easier still.
Same goes for Athletes. Watching sporting events is not relatively expensive including those events billed as Pay-per-view. One can easily watch football or tennis or Baseball with numerous channels available dedicated to them. This is why both actors and athletes are so famous because due to the low cost of their product, a lot of people get to see them.
Architects on the other hand can only offer their services when something needs building and even the most renowned of architects cannot design plans for everyone. Their product is not readily available and so they cannot give it to every single customer with the ease that the entertainers in the sports and acting industry can.