Choose the correct sentence which is built from the words and phrases given:
exhausted batteries / dispose off / a special container / they / consider / toxic waste.
A. The exhausted batteries should be disposed off in a special container because they are considered to be toxic waste.
B. The exhausted batteries should be disposed off in a special container therefore they are considered to be toxic waste.
C. The exhausted batteries should be disposed off in a special container although they are considered to be toxic waste.
D. The exhausted batteries have been disposed off in a special container as soon as they are considered to be toxic waste.