I'm unable to check step 2: Automate Accounts because I'm receiving this error: Challenge Not yet complete... here's what's wrong: 
There was an unexpected error while verifying this challenge. Usually this is due to some pre-existing configuration or code in the challenge Org. We recommend using a new Developer Edition (DE) to check this challenge. If you're using a new DE and seeing this error, please post to the developer forums and reference error id: ZKCVFIZH
 

When testing my process, it performs as expected, but I still receive an error that it didn't work. I've gone through the steps 3 times, and I'm not seeing what I've missed.

I am new to this salesforce  as am trying to  work on trailhead project Battle Station App : 

Then   in the process flow  while i am creating the  Post to Chatter step then  its not showing select This Record. Its showing only user and chatter Group.  Pleae help me out   to solve this problem.

In the Challenge it is requested to make a call to https://th-apex-http-callout.herokuapp.com/animals/:id.

Question is are they expecting a GET call or POST call. Most probably a GET call. But suppose integet pass to the method getAnimalNameById is "45678". How are we to formulate the URL.

Is it Option 1> replace id with value i.e https://th-apex-http-callout.herokuapp.com/animals/:45678
Option 2> pass using equal sign i.e https://th-apex-http-callout.herokuapp.com/animals/:id=45678.

Regardless i am getting the following response {"animal": {"id": 0,"name": "","eats": "","says": ""}}. I want some test data to verify the code is working does any body has that