Describe a problem you've solved or a problem you'd like to solve.
It can be an intellectual challenge, a research query, an ethical dilemma--anything that is of personal importance, no matter the scale.
This question was reworded in 2017-18 admissions cycle, and the current language is a huge improvement.
The prompt use to talk about transitioning from childhood to adulthood, but the new language about a "period of personal growth" is a much better articulation of how we actually learn and mature (no single event makes us adults).
In third place was Option #2 on a setback or failure. Always keep in mind why colleges are asking for an essay: they want to get to know you better.
Nearly all selective colleges and universities (as well as many that aren't overly selective) have holistic admissions, and they consider many factors in addition to numerical measures such as grades and standardized test scores.
At the same time, you'll impress the college admissions folks greatly if you can show your ability to learn from your failures and mistakes.
Be sure to devote significant space to the second half of the question—how did you learn and grow from the experience?
Your "interest" or "talent" could be a passion that has driven you to become the person you are today.
However you approach the prompt, make sure you are inward looking and explain The lessons we take from obstacles we encounter can be fundamental to later success.