During the War of Spanish Succession, why was Charles II's succession to the Spanish throne made more difficult after he was made Holy Roman Emperor?

A. By being both Holy Roman Empire and king of Spain, Charles would have far too much power in Europe.
B. The Holy Roman Empire was still at war with Spain over a decade long territory dispute.
C. Both England and France did not recognize the Holy Roman Empire as a real state.
D. Spain had cut off diplomatic relations with the Holy Roman Empire two decades earlier.