A) The enzyme and substrates move slower as they get cooler, so there is less of a chance of meeting and reacting.

B) Because the substrate is cold, it starts to shiver so much that it can't fit into the enzyme's active site, slowing the reaction down.

C) Because the enzyme is cold, it wears a coat, which changes the shape of its active site, slowing the reaction down.

D) The enzyme's active site is denatured and reactions slow down because the substrates can't fit there.

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