Hello I am Stuck on Permission Set

Hello I am Stuck on Permission Set. I have completed and followed the instruction as listed, however it says; 

"Challenge not yet complete in My Trailhead Playground 1

We can’t find the correct object permissions for account in the ‘Sales User’ permission set group." 

Below is the Challenge: 

Configure Object, Field, and Record Access

As part of your data access configuration, you must give your sales reps access to accounts. You plan to reuse the same permission set for users who’ll need greater access to accounts, so you’ll mute certain permissions for your sales reps using a permission set group. 

You also need to configure your organization-wide defaults for accounts and opportunities so users only see the records they need to.

• Create a permission set:
  • Label: Account Access
  • API Name: Account_Access
  • Add a description (We won’t check for this.)
  • License: -None-
  • Enable Account Object Permissions: Read, Create, Edit, Delete, View All Records, and Modify All Records
  • Enable Account Field Permissions: Read Access and Edit Access for all fields
• Create a permission set group and assign it to the user you created:
  • Label: Sales User
  • API Name: Sales_User
  • Include the Account Access permission set that you created
  • Create a muting permission set in the permission set group and name it Sales User Muted (API Name: Sales_User_Muted)
  • Mute Account Object Permissions: Delete, View All Records, and Modify All Records
  • Mute Account Field Permissions: Edit Access for the Annual Revenue and Customer Priority fields
  • Assign the permission set group to the user you created in the previous unit
• Configure organization-wide defaults:
  • Account and Contract: Visible but not editable for all users.
  • Opportunity: Visible only to record owners and users higher in the role hierarchy.

Can anyone suggest or guide me on this? What did I miss? I couldn't figure it out..