|Question 20Verbal

Source Texts

Text
The relationship between grassland arthropod populations and agricultural fertilizers containing macronutrients-such as nitrogen, phosphorus, and potassium-was the focus of a 2013 study in the blank by the researcher Laura A. Burkle, the study examined a variety of arthropod specimens, which had been collected by hand.
Which choice completes the text so that it conforms to the conventions of Standard English?
United States, led
A
United States and led
B
United States led
C
United States. Led
D