Answer:
The correct answer is letter "d".
Brunelleschi was commissioned to build the dome of the Cathedral of Florence. This work was completed in 1436.
Step-by-step explanation:
In 1418 the authorities of Florence made a call to design the dome, a work that would cover a hole that had the construction. The best architects of the moment came to the call since an economic incentive was offered as well as a recognition that would transcend in time.
Filippo Brunelleschi, presented his proposal that consisted of building two domes, one inside the other, which would give firmness without the need to lift columns or other supports.