Final answer:
Option C (“Hard work and discipline contribute more to school achievement than IQ does”) directly represents the study's findings that grit and perseverance are key to academic success.
Step-by-step explanation:
The best line from the text that supports the idea that grit and perseverance are better predictors of academic success and achievement than talent or IQ is option C: “Hard work and discipline contribute more to school achievement than IQ does.” This choice directly emphasizes the value of effort over innate intelligence, aligning with the findings of the study in question. It makes a clear statement about the importance of persistence and effort, which is what grit and perseverance entail, in relation to academic success.