Which of the Following Is True with Regard to Firm-Level

Which of the following is true with regard to firm-level theories?

A) Firm-level theories are classical theories, widely accepted since the sixteenth century.
B) Firm-level explanations address the question: "How can internationalizing firms gain and sustain competitive advantage?"
C) Firm-level explanations address the question: "Why do nations trade?"
D) Firm-level theories do not address the issue of organizational performance.