Archaeologists believe that the pieces of red – ware pottery excavated recently near Bhavnagar and __________________shed light on a hitherto dark 600-year period in the Harappan history of Gujarat.

• A. estimated with a reasonable certainty as being about 3400 years old,
• B. are estimated reasonably certain to be about 3400 years old,
• C. estimated at about 3400 years old with reasonable certainty,
• D. estimated with reasonable certainty to be about 3400 years old,