Read the abstract of this article.
 
A. [The language barrier – the fact that different countries have different native languages – has been documented in numerous studies as reducing international trade.] B. [This paper investigates the possibility that trade partners with no common native language will overcome the language barrier by communicating in a non-native language.] In today’s world English is the leading candidate to play this role of a lingua franca. C. [By constructing and then employing a new measure of English proficiency covering more than a hundred countries and spanning 30 years, we show that the ability to communicate in English has a strong effect in promoting trade across the globe.] D. [The results thus demonstrate that an acquired proficiency in English can mitigate the impact of historically determined language barriers.]
Which sentence presents the objective of the research?