Which of the Following Best Explains Why We Hear Thunder

Which of the following best explains why we hear thunder?

A) Heat within the lightning channel causes air to expand and then contract violently. The resulting shockwave is heard as thunder.
B) When lightning hits the ground it rapidly heats the ground surface, which expands producing a clap of thunder.
C) Lightning and thunder are produced simultaneously during a thunderstorm.
D) During a thunderstorm, downdrafts move rapidly toward the earth in pulses. These pulses are heard as thunder.