Which of the following is an example of heterogeneous catalysis?
A. Ethylene and hydrogen gases are adsorbed onto the surface of a metal catalyst to accelerate the formation of ethane.
B. An enzyme catalyzes a biochemical reaction that produces the alcohol and CO2 gas in beer.
C. An aqueous acid reacts with a solid metal.
D. An enzyme catalyzes a biochemical reaction inside a human muscle cell.