Which Statement Accurately Describes Alveolar and Systemic Gas Exchanges

Which statement accurately describes alveolar and systemic gas exchanges?

A) In both alveolar and systemic gas exchange, oxygen diffuses out of the blood.
B) In both alveolar and systemic gas exchange, oxygen diffuses toward the blood.
C) In alveolar gas exchange oxygen diffuses into the blood, but in systemic gas exchange it diffuses out of the blood.
D) In alveolar gas exchange oxygen diffuses out of the blood, but in systemic gas exchange it diffuses into the blood.