Final answer:
The length of a StringBuilder cannot exceed its capacity.
Step-by-step explanation:
The correct statement is c. The length of a StringBuilder cannot exceed its capacity.
When a StringBuilder is created, it has an initial capacity, which is the number of characters it can hold without needing to allocate more memory. The capacity can increase as more characters are added to the StringBuilder, but the length of the StringBuilder cannot exceed its capacity.
For example, if a StringBuilder has a capacity of 10, it can hold up to 10 characters. If more than 10 characters are added, the StringBuilder will automatically increase its capacity to accommodate the extra characters.