Correct option is B
The correct answer is "The girls said that they had been walking 8 km each day to reach the campsite."
Explanation:
Direct and Indirect Speech Definition: Direct speech quotes the exact words spoken, whereas indirect speech reports the message in a modified form without quotation marks.
· "Were walking" (past continuous) changes to "had been walking" (past perfect continuous).
· The phrase "each day" remains unchanged.
· Direct: The girls said, "We were walking 8 km each day to reach the campsite."
· Indirect: The girls said that they had been walking 8 km each day to reach the campsite.