Apache gives me 403 Access Forbidden when DocumentRoot points to two different drives

You did not need

Options Indexes FollowSymLinks MultiViews Includes ExecCGI
AllowOverride All
Order Allow,Deny
Allow from all
Require all granted

the only thing what you need is…

Require all granted

…inside the directory section.

See Apache 2.4 upgrading side:

http://httpd.apache.org/docs/2.4/upgrading.html