Correct Answer: D
Explanation:
Choice (A) is incorrect because the plural verb have does not agree with its singular subject
the rising cost.
Both (B) and (C) are incorrect because they turn the sentence into a fragment.
Choice (D) is the correct answer since now the plural verb have agrees with its plural subject
the rising costs.
Choice (E) is incorrect because rising cost is still singular.
The answer is (D).