All four alternatives are basically awful. Native English speakers wouldn't normally use this construction, because it's too unwieldy. No "relational conjunctions" sound natural here.
I don't know any "as fearful/frightened/afraid/etc. as a/the xxxx" that are particularly widespread across region or era. Certainly fear of fire has no special significance in normal speech.
So OP has some work to do constructing a sentence to convey his intended meaning - otherwise the listener is likely to end up thinking "Why is he talking about fire?". I'd suggest maybe...
Those algebra tests scare me like the fires of hell!
Still in the Christian tradition, a more "idiomatic" fear that comes to mind is...
Those algebra tests put the fear of God into me!"