The correct answer is "How Lou Gehrig overcame difficulties to become one of baseball's greatest players?". The other answers carry the properties of a book title or an article which cannot be considered as research paper.
The topic topic that is suitably limited for a research is "<span>Why Lou Gehrig was forced to resign from playing baseball."
The rest of the research topics like (1) t</span>he 5 of baseball and its greatest players. (2) The home run record and batting average of Lou Gehrig. (3) <span>How Lou Gehrig overcame difficulties to become one of baseball's greatest players?</span>
