Company logos are protected by a. patents b. insignias c. trademarks d. copyrights

I would say C
Since copyright can't protect a name, colors or the design of the logo, most simple logos simply do not have the required level of creativity to be considered copyrightable.
Even if your business name is part of your logo, the two must be registered individually. It takes between 10 and 16 months to secure tradematk registration with the USPTO. However, your logo is protected as of the date of filing, not the date of issue, so you can begin using your trademark immediately.

The answer should be d.

Ṅȗṃɞєя 1 ıṡ ѧ ṅȗṃɞєя 2 ıṡ ɞ ṅȗṃɞєя 3 ıṡ b