Why would you use this.fs.extendJSON to modify package.json?

• A. To merge new fields into an existing JSON file without overwriting existing properties
• B. To replace the entire file
• C. To delete specified properties
• D. To read the JSON only

Answer: (A)

Merging into an existing JSON file without overwriting is what this.fs.extendJSON is designed to do. When you call extendJSON on package.json, you provide new fields or updates, and the method reads the current file, combines your data with what's already there, and writes back the merged result. This preserves all existing properties while adding or updating the ones you specify, which is exactly what you want when augmenting a package.json with new configuration.

Replacing the entire file would discard existing properties, deletions aren’t performed by this method (you’d need a different approach to remove fields), and merely reading the JSON wouldn’t modify the file at all.