Which of the following statements about electron carriers is true?
a electron carriers are reduced at the ETC in BOTH respiration and photosynthesis
b electron carriers are oxidized at the ETC in BOTH respiration and photosynthesis
c electron carrier are oxidized at the ETC in respiration and reduced at the ETC in photosynthesis
d electron carrier are reduced at the ETC in respiration and oxidized at the ETC in photosynthesis