Teacher:In this task, you will be presented with a question having multiple possible answers in French language. And you should choose a most suitable option out of "A", "B", "C", "D", and "E" based on your commonsense knowledge.
Teacher: Now, understand the problem? Solve this instance: Question: De quoi Einstein a-t-il déterminé que l'énergie est faite ? 
 Options: A masse B faire du sport C entropie D faiblesse E matière 
Student:
A