[yorwba]

> B) This would allow you to have children read text that includes words they don't know how to read, by providing those words in pinyin.

Indeed. Here's a page from a textbook for second-graders: https://i.imgur.com/g1UlUZP.jpg

It's a story teaching the meaning of the proverb 揠苗助长 (pulling sprouts to help them grow). Some of the characters are annotated with their pinyin above, e.g. 揠 yà or 筋疲 jīn pí. This text in particular is a bit weird in that it only uses 揠 yà in the title and replaces it with 拔 bá in the story, so the reader would have to infer that 揠 yà and 拔 bá are synonyms. I think 拔苗助长 is actually the more common way to write the proverb.