A.I. Explanation:

Option 1: "Specialising in one field of study"

Explanation: This option is incorrect because the text emphasizes the benefits of multilingualism, which include cognitive, cultural, and career advantages, rather than focusing on specialization in a single field. Specializing in one field does not align with the text's theme of broadening opportunities through language learning.

Option 2: "Limiting career choices to local opportunities"

Explanation: This option is incorrect as it contradicts the text, which states that being fluent in several languages opens up international job opportunities. Limiting career choices is the opposite of the benefits highlighted in the text.

Option 3: "Enhancing cognitive abilities and cultural understanding"

Explanation: This option is correct because the text explicitly mentions that learning multiple languages offers cognitive advantages, such as better problem-solving abilities and enhanced creativity, as well as cultural benefits, including greater empathy and appreciation for diverse cultures. These points directly support the answer.

Option 4: "Reducing the importance of cultural diversity"

Explanation: This option is incorrect because it contradicts the text's message. The text highlights that understanding different languages fosters appreciation for cultural diversity, not reduces it. Therefore, this option does not align with the main idea presented.