Final answer:
The word 'remedy' means to correct or improve a problematic situation, and in the sentence, it indicates that William intends to fix an issue.
Step-by-step explanation:
The word remedy as used in the sentence 'William decided to remedy that.' means to take action to correct or improve something that is wrong or problematic. William is looking to find a solution or to fix an issue that has been identified. To remedy is often associated with solving problems or addressing deficiencies in various contexts, ranging from health to legal matters, and in this case, it is about taking steps to resolve whatever 'that' refers to in the context of paragraph 9.