Nhận biết (M1)

To determine the approximate age of sand engravings excavated from a coastal site in South Africa, archaeologist Charles Helm and colleagues collected samples of sediments surrounding the engravings; these samples were then analyzed using a method known as optically stimulated luminescence (OSL) dating. __________ OSL dating indicated that the engravings were between 129,000 and 149,000 years old.

Which choice completes the text with the most logical transition?

• A.

  Similarly,

• B.

  Ultimately,

• C.

  By comparison,

• D.

  In addition,