You need to configure Office 365 to redirect the websit…

Contoso, Ltd. has an Office 365 Enterprise E3 plan. Contoso uses the domain contoso.com for email and instant messaging (IM).
Contoso requires that website visitors who go to http://contoso.com be directed to the company’s Microsoft
SharePoint Online public website.
You need to configure Office 365 to redirect the website requests without affecting the company’s email or IM.
What should you do?

affecting the company’s email or IM”. Email uses MX records. If you have a CNAME record at the root level of a domain, the MX records will not work. www.contoso.com in the Office 365 admin center then configure the redirect to the subdomain. provider and ask if they have a URL redirection service to direct traffic from contoso.com to www.contoso.com. to-use-your-custom-domain-3403c6d5-aaa6-4775-a1cc-c6bda0a99986?ui=en-US&rs=en-US&ad=US

A.
In the SharePoint admin center, rename the public website to http://contoso.com.

B.
In the Office 365 admin center, change the domain purpose for contoso.com to SharePoint.

C.
On the authoritative DNS servers, add a CNAME record for contoso.com.

D.
In the Office 365 admin center, add a new subdomain. Then set up redirection for http://contoso.com to the
subdomain.

Explanation:

In this question, we need to redirect users to the SharePoint public website by using a root domain,
Contoso.com. If we were using www.contoso.com, we could simply configure a CNAME record in DNS.
However, this question states that “You need to configure Office 365 to redirect the website requests without
To use a root domain, we need to configure a redirect. First we need to add a subdomain such as
“If you want users to see your site when they type just the root domain, contoso.com, contact your DNS hosting
Most providers offer URL redirection, and you can check their documentation to learn how to set it up.”
References: https://support.office.com/en-us/article/Rename-your-SharePoint-Online-Public-Website-address-