Which sentence features a present participial phrase functioning as an adjective?

Which sentence features a present participial phrase functioning as an adjective?

a. Blushing furiously, the newcomer couldn’t believe he’d been so gullible.
b. Fatigued after a long day, the woman recuperated with a quiet evening.
c. Our teacher likes to spring impromptu tests on us so we keep studying.
d. The heat radiating from the pavement caused the air to ripple and waver.