Which of the Following Challenges the "Single-System Hypothesis" of Language

Multiple Choice

Which of the following challenges the "single-system hypothesis" of language learning in bilingual children?

A) Bilingual children tend to combine forms from the two languages within the same utterance.
B) Bilingual children acquire both languages more slowly than peers who are only learning one language.
C) Babies in bilingual homes can differentiate sounds from the two languages to which they are exposed.
D) None of the alternatives are correct.