XYZ Corporation is developing a new web application and wants to ensure that it is protected against common security threats like SQL injection and cross-site scripting (XSS). They have decided to implement input validation as a primary security measure. What is the most effective way to implement input validation to mitigate these threats?
Options:
A. Use client-side validation to check inputs before submission to the server.
B. Implement server-side validation to check all inputs against a defined set of rules.
C. Rely solely on web application firewalls to detect and block malicious inputs.
D. Utilize automated testing tools to identify and fix vulnerabilities during development.