Thermofer catalytic cracking process is a __________ process.

In petroleum refinery engineering, the Thermofer catalytic cracking process is a fluidised bed process (Option C).

Fluidised bed catalytic cracking processes involve the use of a fluidised catalyst bed where the catalyst particles are suspended and mixed with the hydrocarbon feedstock. This allows for efficient mixing and contact between the catalyst and the feedstock, promoting the cracking reactions to produce desired products such as gasoline, diesel, and other valuable hydrocarbons.

Therefore, the correct option is Option C: Fluidised bed.