When Proxy Server Settings in a Browser Are Configured Using

When Proxy server settings in a browser are configured using WPAD (web Proxy Auto Discovery) protocol, what has to be specifically guaranteed to ensure security?

A) JavaScript on client's browser must be enabled, otherwise it will not allow to execute proxy configuration script.
B) Hosts (e.g. wpad.mydepartment.mycompany.com, wpad.mycompany.com) should be trusted not to serve malicious wpad.dat files
C) Internet Explorer browser should receive security updates more often than twice a year
D) DHCP must be accessible at the time, when user starts a browser