An administrator is unable to login to vCenter Server when using the vSphere

web client.

The administrator successfully accessed vCenter Server using the client earlier the same day.

What is the most appropriate first step the administrator should take to resolve this issue?

A. Verify the web browser being used has Adobe Flash p

lugin version 11.5 or later

B. Verify the vCenter Single Sign-On service is running on the vCenter Server

C. Verify the vSphere Web Server service is running on the vCenter Server

D. Verify the administrator has permissions configured in vCenter Server