Correct option is B
The correct substitution of the highlighted words is being rough.
Being rough: This is the correct option.
The present participle "being" indicates a continuous action, suggesting that the road is currently rough and influencing their decision to abandon the journey.
· be rough: This is incorrect because it's not a complete verb phrase and doesn't convey the correct tense.
· was rough: This implies a past action, suggesting that the road was rough at some point in the past but might not necessarily be rough now.
· had been rough: This suggests a past perfect tense, implying that the road was rough before a certain point in the past, but the sentence doesn't provide context for this.
Conclusion:
Option (b) being rough is the most appropriate choice because it accurately conveys the ongoing condition of the road and its direct impact on their decision to abandon the journey.