Use the Following Information to Answer the Next Questions

Use the following information to answer the next questions.
In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate 1) loses a carbon, which is given off as a molecule of CO₂, 2) is oxidized to form a two-carbon compound called acetate, and 3) is bonded to coenzyme A.
-How does pyruvate enter the mitochondrion?

A) active transport
B) diffusion
C) facilitated diffusion
D) through a channel
E) through a pore