It's not showing Open GL Preview

It’s the first time that I ask a question, please help me!
blender 2.79.b
Ubuntu 18.04.1 LTS
procesor Intel® Core™ i7-6700 CPU @ 3.40GHz × 8
GeForce GTX 960/PCIe/SSE2
64 bit.

This is my problem VSE Properties/ Scene Preview/Render it’s not showing Open GL Preview option :tired_face: