Answer:
The right answer is, A. Hayamos ayudado.
*Me alegro de que nosotros hayamos ayudado a organizar este evento.
Explanation:
To complete the sentence, they give us the verb that we must use, so we must identify the person in the sentence and the verb tense to be able to conjugate it in a logical way and that it has a relationship with what is being expressed.
A ti no te gusta hablar por telefono.
Nositros no / llegar al centro comercial
-Nocotros no sabemos llegar a la residencia estudiantil
yo / el profesor de literatura
-Yo conozco al profesor de literatura
Elena y Maria Victoria / patinar en linea
-Elena y Maria Victoria saben patinar en linea
(Hope this helps although I don't know if they are correct)
Good luck.