Selected financial information is provided below for three major pharmaceuticals: Glaxo Smith Kline (Britain), Sanofi (France), and Pfizer (U.S.). Glaxo Smith Kline€™s numbers were taken from the 2014 SEC Form 20-F, it uses IFRS, and the numbers are expressed in British pounds; the numbers for Sanofi were also taken from the 2014 SEC Form 20-F and it too uses IFRS, but the numbers are expressed in euros; Pfizer is a U.S. company that uses U.S. GAAP, and the numbers are expressed in dollars and were taken from the 2014 SEC Form 10-K. As of the end of 2014, 1 U.S. dollar was equivalent to 0.64 British pound and 0.83 euro. All numbers are in billions.

a. Which company is the largest, and by how much?
b. Explain why it may be difficult to clearly state which is the largest.

Pfizer Sanofi 33.8 GlaxoSmithKline Sales 49.6 23.0 Total assets Shareholders' equity 40.7 169.3 97.4 71.6 4.9 56.3