quizzes: expand all 35 quizzes to 15 questions each

OPS-1 through OPS-10, OS-2, OS-3 went from 5 → 15.
OS-1, OS-4 through OS-11, SEC-1 through SEC-11, TRB-1 through TRB-4 went from 7 → 15.
Questions cover exam-weight scenarios not duplicated from original content.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

quizzes/SEC-11-quiz.md

@@ -56,6 +56,62 @@ B. Quick format
 C. Screen brightness  
 D. Proxy  
 
+8. What does HTTPS ensure when visiting a website?
+
+A. The website is free of malware  
+B. The connection between the browser and server is encrypted  
+C. The website is in the trusted vendors list  
+D. The download is automatically scanned  
+
+9. Why are browser updates important from a security perspective?
+
+A. They remove the need for passwords  
+B. They make certificate warnings safe to ignore  
+C. They physically secure the router  
+D. They can patch security vulnerabilities in the browser  
+
+10. A user visits a legitimate news site and gets a malware pop-up. What is the likely cause?
+
+A. The user's screen is too bright  
+B. Malvertising — malicious ads served through ad networks on legitimate sites  
+C. The browser needs a new printer driver  
+D. The SSL certificate expired  
+
+11. Why is it risky to save passwords in a browser on a shared computer?
+
+A. It slows the browser  
+B. Other users or malware could access saved credentials  
+C. It disables HTTPS  
+D. It requires a GPU  
+
+12. Which browser feature warns users when they attempt to visit a known phishing or malware site?
+
+A. Download manager  
+B. Safe Browsing or SmartScreen filter  
+C. Private mode  
+D. Tab management  
+
+13. A user's browser homepage changed and unknown toolbars appeared after installing freeware. What most likely happened?
+
+A. A scheduled update ran  
+B. A browser hijacker was installed bundled with the freeware  
+C. The DNS server changed  
+D. The user's account was moved to a domain  
+
+14. What is the safest action before clicking a link in a suspicious email?
+
+A. Click it to check if it loads correctly  
+B. Hover over the link to preview the URL and verify it matches the expected destination  
+C. Forward the email to verify with others  
+D. Save the attachment first  
+
+15. What is the purpose of certificate pinning in security-conscious applications?
+
+A. Speed up TLS handshakes  
+B. Prevent man-in-the-middle attacks by accepting only a specific certificate  
+C. Allow self-signed certificates everywhere  
+D. Replace HTTPS with HTTP for speed  
+
 ## Answer Key For Instructor
 
 1. C
@@ -65,4 +121,12 @@ D. Proxy
 5. C
 6. B
 7. D
+8. B
+9. D
+10. B
+11. B
+12. B
+13. B
+14. B
+15. B