Final answer:
David Ortiz's nickname is Big Papi, a term of endearment and recognition of his impact on the Boston Red Sox, similar to Babe Ruth's profound influence on baseball.
Step-by-step explanation:
The nickname of the Red Sox player David Ortiz is A) Big Papi. David Ortiz, also famous as Big Papi, is known for his charismatic presence in baseball and his significant contributions to the Boston Red Sox. While Babe Ruth, another legendary figure in baseball, was known for being arguably the greatest hitter in Major League Baseball and had a career that started as a pitcher for the Red Sox before a controversial trade to the New York Yankees, David Ortiz made his own mark primarily as a designated hitter and first baseman with a charismatic and larger-than-life persona, earning the loving moniker 'Big Papi'.