Answer:
After travelling to different countries and finding differences between the conditions of work in the united states and the developing countries he experienced b) social responsibility differences betwee similar firms, but in different countries.
Explanation
First, we have to analyze everything.
A) he didn't mention any act of corporate philanthropy so A) is wrong.
C) he didn't discover any difference in corporate social initiatives, he found a difference in working conditions. So C) is wrong.
D) he is not using media to let the public know the differences between the working conditions in developing countries and the United States. So D) is wrong he is not a whistleblower.
b) he found differences between the operation procedures in different countries. Now, this is where the statement gets tricky. It says social responsibility and social responsibility impacts the society in which the business is located. But, the members o that same company form part o the society, so indirectly they are benefited in their life and working conditions.