XML is case-sensitive for all element and attribute names. and are different tags, and 'ID' and 'id' are different attributes. This is specified in the XML recommendation and parsers enforce this strictly.

This JSP declares an instance variable x initialized to 0. On first access: x starts at 0, x++ prints 0 then becomes 1, jspInit() prints x++ (1) then x becomes 2. System.out.println(x) outputs 2. End of first request: x=2. On second access: x starts at 2, x++ prints 2 then becomes 3. jspInit() prints x++ (3) then x becomes 4. System.out.println outputs 4. The expression <%= x++ %> outputs 3 (current value before increment). So second access shows 3 in the web page.

Standard JSP custom tag libraries use TLD (Tag Library Descriptor) files, typically stored in WEB-INF or META-INF. The question mentions non-standard 'ps:' tags, but if this is a standard JSP question about TLD files, option A is correct. However, 'ps:' is not a standard JSP tag prefix.

XML tags are strictly case-sensitive. The opening tag <NAME> must match the closing tag </NAME> exactly. Distractors mismatch cases between opening and closing tags, which violates XML syntax rules and causes XML parsing errors.

In Java EE applications, the application.xml deployment descriptor (part of the EAR structure) defines the context root for web modules. The web.xml configures servlet-level settings but not the application context root. Option B is correct.