The answer is C. “Un” is a prefix, and “ed” is the tense.
Answer: لا أستطيع أن أفعل هذا لأنني لست أنت ولا أعرف ما هو أعمق تأثير حدث عليك.
Explanation:
A decrease in the number of foreign tourists means, among others, the decrease in the revenue from tourism. Additionally, this will mean that the infrastructure in the touristy areas will get worse, as there will be less incentive to upkeep it. Businesses will earn less and some businesses might disappear altogether.
Generally, the effect on the region would be negative.