XboX1. We are starting the sentence with an appositive modifier (Largest of all land carnivores) that points to the noun the Alaskan bear
2. Then we have a couple of verb+ing modifiers that both modify the noun namely the Alaskan bear
3. Now you get the independent sentence, namely, the Alaskan brown bear is…..
Therefore, this is a simple sentence with adjectival modifiers appearing before the main clause.
The important thing here to remember is that the modifiers will not have any verb. If the modifiers have any verb, then the sentence will become comma splices( run-ons) since there will be two clauses joined by a comma. That is precisely the reason why choices B, C, D and E are all wrong
A.Largest of all land carnivores, weighing up to 1500 pounds and measuring
B.Largest of all land carnivores, weighing up to 1500 pounds and it
measures C.Largest of all land carnivores, it weighs up to 1500 pounds and
measures D.It
is largest of all land carnivores, weighing up to 1500 pounds and measuring
E.It
is largest of all land carnivores,
weighs up to 1500 pounds and
measures HTH