The questions asks for possible translations of "Liliane's son, whom I told you about, lives in Angers."?The following option is marked incorrect, but I don't understand why.
Le fils de Liliane, qui je t'ai parlé de, habite à Angers.
I get that I need to distinguish between Liliane and her son, so the best option is to use "duquel", but if "dont" and "à qui" are accepted, why is "qui" not accepted?