Getting secondary citations right

i have some questions regarding secondary citations (in an computer science research paper that should be published in a journal). I know that they should be avoided when possible, but it is not always that easy.

Example: Article A says: "The average value of ... in ... is ... [B]. [C]s study says that in ... the value is ...".

This statement is exactly what i need for my paper. If i read [B] and [C], i see that [A] cited them correctly and if i would have found these two other articles myself, i would have written the same.

Now how to cite this in a correct way?

1. "[B] and [C] say (cited in [A]) ..." (and do a "bad" secondary quote)


2. "[B] and [C] say ..." (and neglect the investigation done by [A] and peform citation plagiarism)


3. "[A] says ..." (and neglect that the data was the achievement of [B] and [C])


4. "[A] says based on the findings of [B] and [C] ... " (and do a secondary quote again)

Greetings