Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that best combines each pair of sentences in the following questions.
Human beings have destroyed the environment for a long time. They are now paying a high price for this
A. Because having destroyed the environment for a long time, human beings are now paying a high price for this
B. Having destroyed the environment for a long time, human beings are now paying a high price for this
C. On destroying the environment for a long time, they are now paying a high price for this
D. After being destroyed for a long time, the environment is now paying a high price