I believe the answer is "A".

David's response is to managing attachments in Salesforce which doesn't have to do with Knowledge Articles.

The question does signify that most of their knowledge articles use images so its important they have to be migrated in properly. Therefore to ensure images don't get "dropped / excluded" they have to be referenced in the .html file.

Key Points from the Salesforce Help Link:
1. The .zip file can’t exceed 20 MB and the individual, uncompressed, files within the zip file can’t exceed 10 MB.
2. Images must be .png, .gif, or .jpeg files.
3. Each image file can’t exceed 1 MB.
4. If an .html file references an image that's missing, the related article is imported without the image.
5. To import images, include the images in an .html file using the <img> tag and src attribute. Ensure that the src value is a relative path from the .html file to the image folder.


https://help.salesforce.com/s/articleView?id=sf.knowledge_article_importer_02csv.htm&type=5

B
The default size limit is 25MB
https://help.salesforce.com/s/articleView?id=000331184&type=1

"A" is false because is not mandatory that the images be referenced (not inserted) in a single html file. You can import multiple html files.