In the mid-fifth century, Rome was threatened by Hunnish troops who, led by Attila the Hum, demonstrated his military superiority over the weakened, recently conquered city.
A: who, led by Attila the Hum, demonstrated his military superiority
B: which, led by Attila the Hum, demonstrated their military superiority
C: that Attila the Hum led, who demonstrated his military superiority
D: that Attila the Hum led in demonstrated of their military superiority
E: that were led by Attila the Hum, who demonstrated his military superiority
OA: B
A, C and E are incorrect because of HIS. What about B and D?
Can WHICH refer to TROOPS? Why?
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