How to get the vertically-oriented tree using d3.js

Question

The following url is going to get horizontally-oriented tree. My requirement is however to get a vertically-oriented tree using d3. Please suggest a proper valid solution

Answer 1

I know its been a while since you asked the question, but just in case I would like to bring to your attention a diagram that I made:

The code in on codepen. If you have any questions regarding the code, please let me know.