Question #N523

The discovery of the fossilized remains of a mixopterid eurypterid, known as a sea scorpion, on the paleocontinent of Gondwana, was significant because it expanded the understanding of mixopterids’ geographical distribution. 

Which of the following is the most effective way to revise the sentence so that it conforms to the conventions of standard English?
A. The discovery of the fossilized remains of a mixopterid eurypterid, known as a sea scorpion, on the paleocontinent of Gondwana was significant because it expanded the understanding of mixopterids' geographical distribution.
B. The discovery of the fossilized remains of a mixopterid eurypterid, known as a sea scorpion, on the paleocontinent of Gondwana, was significant because it expanded the understanding of mixopterids’ geographical distribution.
C. The discovery of the fossilized remains of a mixopterid eurypterid, known as a sea scorpion on the paleocontinent of Gondwana, was significant because it expanded the understanding of mixopterids’ geographical distribution.
D. The discovery of the fossilized remains of a mixopterid eurypterid, known as a sea scorpion, on the paleocontinent of Gondwana, was significant, because it expanded the understanding of mixopterids’ geographical distribution.