Explanation/Reference:
Explanation:
A: A Composed Look is made up of:
Master Pages

CSS

Color palettes

Font palettes

D: Background image
This means we can package a master page with its CSS, color palettes, font palettes and background image and have it deployed in the enterprise. With Composed Looks, you can now offer your Power Users a list of branded looks and allow them to choose an appropriate look as well as giving them limited control to make changes to the colors, image or font. You could be providing the Composed Looks.
E: To map a master page to a SharePoint site
In Site Settings for the designated site, under the Look and Feel section, choose Master Page.
On Site Master Page Settings, select one of the two options for the Site Master Page or System Master Page sections:
Inherit site master page from parent site Choose this option if you are configuring a child SharePoint site and want to use the parent master page.
Specify a master page to be used by this site and all sites that inherit from it Choose this option if you want to map a specific master page to the site, or if you want to map a specific master page for administrative pages.
A drop-down box named Default or All Channels is available for you, depending on your site or system configuration, so you can select a specific master page stored in the master page gallery. Select the desired master page from the drop-down box.
Choose OK.