Sentence B is the correct option. When using "however" to write a compound sentence, we should write a semi-colon before and a comma after it. When "however" is used at the beginning of a sentence, we should write a comma following it.
Something necessary or indeipensable: food shelter, and other necessities of life. The fact of being necessary or indispensable; indispensability: the necessity of adequate housing.
I think the answer is the first one, the workshop was not a pleasant environment for the children
I think this because in the excerpt it’s talking about how normally they don’t have a big breakfast, she wasn’t talking in her normal nasty voice, they would’ve be chained to their looms etc so it’s basically saying normally this place is a dark and not an enjoyable place for them but that day was for some reason was different. But you can infer that it wasn’t a pleasant environment for them by what goes on for them normally.