L1 B ,L1A --Extension and Conversion Success Rate

[karthikgk]

All,

I am Currently on L1B _Blanket.My Visa expires on Dec.I am planning to do an L1B extension.There are other thoughts of doing an L1A conversion as I got promoted recently.I have few queries regarding that.Kindly help me here. Thanks for helping me in advance
1)Whats the success rate of L1B extension
2)Whats success rate of L1A conversion
3)What all Questions we may need to be prepared for L1B to L1A conversion
4)Since I got promoted recently and activities am doing are managerial activities ,is that a reasonable answer for L1B to L1 A conversion

Thanks
Karthik