A.In the pub/static folder

B.In the Magento core folder

C.In the theme's web/css/source directory

D.In the vendor directory

A.Allows the extension of the default theme without modifying the core files.

B.Ensures backward compatibility when upgrading Magento versions.

C.Allows the creation of multiple themes without inheriting any files.

D.Reduces code duplication by reusing components of the parent theme.

A.theme.xml

B.both B and C

C.registration.php

D.layout.xml

A.Overriding is recommended for minor changes.

B.Extending removes the core functionality.

C.Overriding completely replaces the original XML file.

D.Extending adds new elements without modifying existing elements.

A.if-else conditions using {{if}} ... {{else}} ... {{/if}}

B.if conditions using {{if}} ... {{/if}}

C.if-else conditions using {{if}} ... {{else}} ... {{/endif}}