Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

An arbitrageur will most likely execute a trade when:
Option A:transaction costs are low.
Option B:costs of short-selling are high.
Option C:prices are consistent with the law of one price.

Answer: A