In ISO 26262 ASIL decomposition, which combination is permitted for splitting an ASIL D safety requirement and allocating it to two sufficiently independent redundant elements?

Answer: B. ASIL B(D) and ASIL B(D)

In ASIL decomposition, the same safety requirement can be allocated at lower ASILs to mutually independent redundant elements. The permitted decompositions of ASIL D are B(D) and B(D), C(D) and A(D), and D(D) and QM(D). The (D) in parentheses indicates the original ASIL. A dependent failure analysis must show that the two elements will not fail simultaneously from the same cause. Also, the targets for the random hardware failure metrics remain those of the original ASIL D even after decomposition.