Although the tarantula rarely bites and is much less venomous than either the black widow or the brown recluse, its fangs are of such size and power that they can be a cause of mechanical damage.

A. its fangs are of such size and power that they can be a cause of mechanical damage
B. its fangs are so large and powerful as to cause mechanical damage
C. such are the size and power of its fangs that they can be a cause of mechanical damage
D. their fangs are large and powerful enough to cause of mechanical damage
E. such are the size and power of its fangs that it can cause mechanical damage

I eliminated all but A and B and chose A over B. The correct answer is B.

IMO the answer choices A and B are very subtle. Please let me know the difference between A and B.

Thanks.