You Lose Your Left Sandal During a Hot Afternoon at the Beach

Multiple Choice

You lose your left sandal during a hot afternoon at the beach. Thus, you must hike back to your vehicle with one bare foot across the burning sand. Why does the bare foot get so much hotter?

A) The sandal insulates the right foot from the hot sand.
B) The sandal conducts heat away from your right foot and into the sand.
C) The sandal is in the shadow of your foot, but the sand is not.
D) Heat flows from your right foot into your left foot and then out into the sand, thus cooling off your right foot.