Why did you apply for the job?

I am assuming that the intent is to ask how to answer that question during an interview. Here's my best bet, in a broad sense:

As I went through the job description and the candidate requirements, I strogly belived that I was a suitable candiate based on my credentials, skills-set and experience. Moreover, I see myself deemed fit to be a part of the vision of the company (make sure you have read it and are convinced) and be a contributing factor towards its growth while also allowing for my professional and personal all-round development.