HOTSPOT
You are the SharePoint Online administrator for Contoso, Ltd. The company purchases an Office 365
Enterprise El plan.
The public-facing website must use SharePoint Online and the custom domain contoso.com.
You need to configure the DNS settings for the public-facing SharePoint site.
How should you configure the DNS settings? Select the appropriate options from each list in the answer area.
Answer: 
Explanation:
in my opinion is correct
Looks to be the correct answer.
The answer is correct, you can see the full explanation here:
https://support.office.com/en-za/article/Use-a-custom-domain-name-to-rename-your-Office-365-Small-Business-public-website-58f5adda-e52a-49ca-9244-93c7d93e3272?ui=en-US&rs=en-ZA&ad=ZA
CNAME, http://www.contoso.com, contoso-public.sharepoint.com