Acabar de + infinitive verb is used to say:

question 49 options:

a)
what someone has just done

b)
what someone will do

c)
what someone is doing

The correct answer is: a)  What someone has just done.

Explanation:

Acabar de + infitive is used to express an action that has just happened.

Acabo de llegar a casa. (I have just come home.)

Acaban de llamar a mamá. (They have just called mum.)

To form this expression, we use the verb acabar in the present tense:

1. acabo

2. acabas

3. acaba

1. acabamos                                      + DE + infinitive

2. acabáis

3. acaban

It refers to the actions that have just occurred (according to the moment of speech).