Question

a well-respected research organization reports that in more than twenty european nations, students learn at least three languages in school.
strong source information and a strong reporting verb
weak source information
a weak reporting verb
no source information or reporting verb

Explanation:

The sentence has a "well - respected research organization" as the source (strong source information) and "reports" as the reporting verb (strong reporting verb). So it fits the "Strong Source Information and a Strong Reporting Verb" option.

Answer:

Strong Source Information and a Strong Reporting Verb