Question #N603

The scientist had discovered a new species of butterfly, but it was so small that it could only be seen with a microscope. The scientist also discovered that the butterfly was only active at night and that it had a unique, very complex mating ritual. The scientist’s findings were published in a scientific journal, and they were soon picked up by the popular press.

Which choice best combines the sentences at the underlined portion to create a grammatically correct and stylistically effective sentence?
A. and it was only active at night, and it had a unique, very complex mating ritual.
B. being only active at night and having a unique, very complex mating ritual.
C. only active at night, and it had a unique, very complex mating ritual.
D. active only at night, and it had a unique, very complex mating ritual.

Correct Answer is: C

The correct answer is C. The original sentence uses two unnecessary commas. The phrase "only active at night" is a nonessential element that describes the butterfly and can therefore be set off with commas. "And it had a unique, very complex mating ritual" is an independent clause, which cannot be joined to the main clause with just a comma. This creates a comma splice. The only option that removes the unnecessary commas and corrects the comma splice is choice C.