Answer:
The correct answer is (C).
To answer this question, we must go over each statement and decide whether (1) it follows from the passage (2) it is accurate.
Statement A - the passage links improvement in brain development and the acquisition of language, so the statement follows from the passage. However, the passage more specifically links improvement in ’executive functions’ with two or more languages. Consequently, statement A might not necessarily be the most accurate answer, and it is advisable to go over the remaining distractors before making a decision.
Statement B - does not follow from the passage, as the passage states that bilinguals ’need to select the correct language continually’; however, it doesn't say that they have difficulties doing so.
Statement C - does follow from the passage and is more accurate than statement A. Therefore it is the correct answer.