Answer:
Letter a is correct. His idea solved a problem.
Explanation:
In this case, the emergence of the Netflix company came about because of a problem its creator Reed Hastings had when returning a DVD.
The creation of the company arose out of necessity and solved the problem of people who forgot to return rented DVDs on time and therefore had to pay high interest rates. Netflix's success lies in offering subscription plans so that subscribers have unlimited streaming access to thousands of movies and series, which became popular around the world and made the old dvd rental system virtually extinct.