[Q] HELP! "USB debugging" mode don't show up topic

i need help. i'm about to root my phone samsung exhibit II 4g but when i check the USB debugging mode and connect now my phone on the computer the "USB Debugging mode" is not showing in the notification (above the screen together with the battery, signal and clock) instead it just says "USB connected". So i always end up not rooting my phone after using zerg rush. I already tried doing factory reset on my phone and already installed samsung USB drivers. What should i do? please help me :(