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/OS-7-quiz.md

@@ -56,6 +56,62 @@ B. Metered connection
 C. Disk quota  
 D. Fast Startup  
 
+8. Which command releases and then renews a DHCP lease?
+
+A. `ipconfig /all` then `netstat`  
+B. `ipconfig /release` then `ipconfig /renew`  
+C. `nslookup` then `tracert`  
+D. `net use` then `hostname`  
+
+9. A user can reach internal resources but cannot browse the internet. What is the most likely cause?
+
+A. Incorrect subnet mask  
+B. Default gateway is missing or incorrect  
+C. DNS is set correctly  
+D. APIPA address assigned  
+
+10. Which command clears the local DNS resolver cache?
+
+A. `nslookup /flush`  
+B. `ipconfig /flushdns`  
+C. `netstat -flush`  
+D. `gpupdate /force`  
+
+11. A Windows workstation needs to use a static IP. Where is this configured?
+
+A. Device Manager  
+B. Programs and Features  
+C. Network adapter properties > TCP/IPv4  
+D. Windows Update  
+
+12. Which network profile automatically applies the most restrictive Windows Firewall rules?
+
+A. Domain  
+B. Private  
+C. Workgroup  
+D. Public  
+
+13. A user cannot reach a network printer by name but can reach it by IP address. Which service is most likely at fault?
+
+A. DHCP  
+B. DNS  
+C. NTFS  
+D. BitLocker  
+
+14. Which command tests basic network connectivity to another host?
+
+A. `netstat`  
+B. `ping`  
+C. `gpresult`  
+D. `taskkill`  
+
+15. A shared folder should allow all domain users to read but only IT staff to write. Which feature combination handles this?
+
+A. DNS server settings  
+B. DHCP scope  
+C. Metered connection  
+D. Share permissions combined with NTFS permissions  
+
 ## Answer Key For Instructor
 
 1. D
@@ -65,4 +121,12 @@ D. Fast Startup
 5. D
 6. C
 7. B
+8. B
+9. B
+10. B
+11. C
+12. D
+13. B
+14. B
+15. D