Which of the protein complexes labeled with Roman numerals in Figure 7.2 will transfer electrons to O2? Naim 06:32 AP Biology Chapter 7 Which of the protein complexes labeled with Roman numerals in Figure 7.2 will transfer electrons to O2? A) complex II B) complex IV C) complex III D) complex I E) All of the complexes can transfer electrons to O2. Answer: B Learn More : Share this Share on FacebookTweet on TwitterPlus on Google+