I am doing the Assign Accounts, Rules, and Users to Territories module on Trailhead and keep getting the following error:

Challenge Not yet complete... here's what's wrong: 
There was an unexpected error in your org which is preventing this assessment check from completing: System.QueryException: List has more than 1 row for assignment to SObject

I don't know what this bit means: System.QueryException: List has more than 1 row for assignment to SObject

I can't get passed challenge 6 in the Business Administration Specialist superbadge. 

Here is the error:  Challenge Not yet complete... here's what's wrong: 
Couldn't find the necessary multiple-choice post.

The requirement was "Within the collaboration space, create a multiple-choice post gauging the team’s familiarity with residential market products. Use the question "Which product are you most comfortable selling?" with the options Home Array, Home Battery, Home Starter Kit, and Home Starter Kit Deluxe." The only thing I can think of is a poll? But this is multiple choice. Am I missing something obvious??

I am doing the Assign Accounts, Rules, and Users to Territories module on Trailhead and keep getting the following error:

Challenge Not yet complete... here's what's wrong: 
There was an unexpected error in your org which is preventing this assessment check from completing: System.QueryException: List has more than 1 row for assignment to SObject

I don't know what this bit means: System.QueryException: List has more than 1 row for assignment to SObject

I can't get passed challenge 6 in the Business Administration Specialist superbadge. 

Here is the error:  Challenge Not yet complete... here's what's wrong: 
Couldn't find the necessary multiple-choice post.

The requirement was "Within the collaboration space, create a multiple-choice post gauging the team’s familiarity with residential market products. Use the question "Which product are you most comfortable selling?" with the options Home Array, Home Battery, Home Starter Kit, and Home Starter Kit Deluxe." The only thing I can think of is a poll? But this is multiple choice. Am I missing something obvious??

Help me to solve this error!

Hear is my report!