To answer this question, we need to understand the structure of a PL/SQL block.
A PL/SQL block consists of four main parts: DECLARE, BEGIN, EXCEPTION, and END.
The DECLARE section is used to declare variables, cursors, and other PL/SQL objects. It is optional in a PL/SQL block.
The BEGIN section is where the executable statements of the block are placed. It is also optional in a PL/SQL block.
The EXCEPTION section is used to handle exceptions that may occur during the execution of the block. It is optional in a PL/SQL block.
The END section marks the end of the block. It is a required part of a PL/SQL block.
Based on the given options, let's go through each one:
Option A) DELCARE and BEGIN - Both DECLARE and BEGIN are optional parts of a PL/SQL block. This option is incorrect.
Option B) DECALRE and EXCEPTION - Both DECLARE and EXCEPTION are optional parts of a PL/SQL block. This option is correct.
Option C) EXCEPTION and END - The EXCEPTION section is optional, but the END section is required. This option is incorrect.
Option D) BEGIN and END - The BEGIN section is optional, but the END section is required. This option is incorrect.
Therefore, the correct answer is B) DECALRE and EXCEPTION. These parts are optional in a PL/SQL block.