|Question 18Verbal

Source Texts

Text
The size of bird eggs varies widely across species, and the researchers,        computer imaging to compare the lengths of eggs from species like Chloroceryle americana and Francolinus coqui, aimed to shed light on the evolutionary basis for such variation.
Which choice completes the text so that it conforms to the conventions of Standard English?
using
A
to use
B
use
C
used
D