A) the agreement between France, England, and Russia
Explanation:
<em>Entente ; a friendly understanding or informal alliance between states or factions.</em>
Your answer would be "A" because as described on wikipedia and other outside sources, a triple entente involves France, England, and Russia and their informal understanding between all three. It was built upon the Franco-Russian Alliance of 1894 and the Entente Cordiale of 1904 between Paris and London.