It turns out that a new directory was created during the upgrade process under: "/var/www/". That new directory is labelled: "html". Moving "index.html" into the directory: "/var/www/html" solved the issue.
The solution was found in this post: "Why is my Apache not working after upgrading to Ubuntu 14.04?" This post also refers to: "Where to place my local website starting with the 2.4.7 version of apache2?"
More information can be found here: "HTTPD - Apache2 Web Server".
In searching for a solution to the broken link, I was able to solve two other minor irritants with Apache that did not seem to cause any problems other than occasionally spitting an error message.
One error message was: "AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1. Set the 'ServerName' directive globally to suppress this message." The solution was contained in this post: "Problem with restarting Apache2 [duplicate]". The solution is to add the line: "ServerName localhost" to the "/etc/apache2/apache2.conf" file.
# Global configurationThe other error message: "AH00671: The Alias directive in /etc/apache2/conf-enabled/phpmyadmin.conf at line 3 will probably never match because it overlaps an earlier Alias."
This error originated from the file: "/etc/apache2/conf-enabled/httpd.conf". Turns out that this file has been deprecated. For whatever reason, it was still on my computer. Commenting out the line below, by adding the "#" symbol at the beginning of the line resolved the error message.
# Include /etc/phpmyadmin/apache.confShould you note any errors in what I wrote or have other comments, please comment.