Which of the following ABAP SQL snippets is syntactically correct for parameter value assignment?

The choice that correctly demonstrates syntactical usage for parameter value assignment in ABAP SQL is the first snippet. This option uses a traditional SQL statement structure that ABAP recognizes for parameter passing. It correctly formats the assignment of the parameter p_date with a literal value in a straightforward way.

In this case, the assignment of p_date is done by directly tying it to a specific date string without any additional syntax requirements or errors. The simple assignment using the equals sign is customary in SQL statements, which makes this option a clear and syntactically valid method of passing parameters in ABAP.

The other choices have various issues with syntax or use of incorrect structures. For instance, the second option tries to use a method call to retrieve the system date thus introducing brackets that suggest a function call which is not applicable for parameter assignment in this context. The third option employs a syntax that looks like it is pulling from session variables; however, it misuses the parameter assignment operator. Lastly, the fourth option uses an invalid date format that does not comply with date standards, making it an unacceptable choice both syntactically and semantically.