Final answer:
A good thesis is supported by many pieces of reliable evidence.
Step-by-step explanation:
The correct statement about historical theses is: d) A good thesis is supported by many pieces of reliable evidence.
A historical thesis is a tentative statement about reality and cannot be proven to be true. However, a good thesis is supported by multiple pieces of reliable evidence. The more evidence that supports a thesis, the more likely it is to be true. It is important to consider the quality and reliability of the evidence when evaluating historical theses.