Concept:Indirect speech requires changing tenses, pronouns, and time/place words to match the reporting past tense.
Explanation:Start from the direct sentence: "We have been walking... are just around this corner... we will be there."
First, change the reporting verb to past tense: "said that."
Next, change pronoun "we" to "they" because the guide is speaking about the group.
Change present perfect continuous "have been walking" to past perfect continuous "had been walking."
Change present tense "are" to past tense "were."
Change demonstrative "this" to "that."
Change future tense "will" to conditional "would."
Keep the adverb "just" unchanged.
Combine all parts with correct conjunction "but" and "and."
The resulting sentence matches option A exactly.
Option B keeps direct speech tenses and pronouns wrongly.
Option C fails to change "are" and "will" to past forms.
Option D incorrectly uses past continuous instead of past perfect continuous.
Thus, only option A follows all rules.
Answer:A. The tour guide said that they had been walking for hours, but the ruins they had been looking for were just around that corner, and they would be there in a few minutes.