Final answer:
The historical context of the question refers to the early 15th-century competition for the second set of doors for the Florence Baptistery, with known entries from Lorenzo Ghiberti and Filippo Brunelleschi. However, the exact number of subcontractors bidding is not given, therefore an accurate answer cannot be determined from the provided details.
Step-by-step explanation:
The question appears to be a historical reference to the competition for the commissioning of the second set of bronze doors for the Florence Baptistery, which took place in the early 15th century. In the context of the information provided, the competition for the doors occurred much earlier and was between two main artists of that time, Lorenzo Ghiberti and Filippo Brunelleschi.
It is not well-documented exactly how many individuals or subcontractors were bidding on the overhead doors during that time, but from the given information, we know at least two panels that survived were attributed to these prominent figures in art and architecture. Ghiberti's work was ultimately chosen for the commission, and these doors would come to be known as the 'Gates of Paradise'. Therefore, the question does not provide sufficient information to accurately determine the number of subcontractors bidding.