For this case we have the following expression:
_______________ task that I am doing is impossible I do not know what I am going to do.
What we should do is choose the correct word to fill in the blank.
As we refer to something that is close to us, the correct word is:
This
The complete sentence is:
This task that I am doing is impossible, I do not know what I am going to do.
The translation of the sentence in Spanish is:
Esta tarea que estoy haciendo es imposible no sé que voy hacer.
Answer:
b. Esta