FPGA part number unavailable in Quartus 18.1

I want to use a Cyclone V device: 5CGXBC3B6U15C8N However, in Quartus 18.1 device selection, the ...C8 speed variant is not available.

Does this mean that:

a. the device I want to use does not exist / is not available ?

b. QP 18.1 does not support the device ?

b1. when will it be supported in QP ?

b2. should I select another device in QP to program the above device that I want to use ?

Thanks