Nhận biết (M1)

In economics, mustard seeds are considered a commodity because they are essentially interchangeable, “essentially” being a word that admits a degree of latitude. In 2021, researchers J. Shorish, M. Stephenson, and M. Zargham devised a mathematical model of fungibility (interchangeability) that would account for such variation. Distinguishing “exactly the same” and “nearly the same” commodities—whether crops, lumber, or precious metals—__________ among their primary aims.

Which choice completes the text so that it conforms to the conventions of Standard English?

• A.

  having been

• B.

  being

• C.

  was

• D.

  were