Use reasoning to answer the following question.
He kept plugging away in his cubicle, it seemed he was the only person not called into the what?\nOptions:\n- building\n- conference\n- assessment\n- demonstration\n- garage

conference
To keep plugging away means to continue working steadily in one place.

Conferences and meetings are usually held at work.

When one is not called into a conference, they keep working in his cubicle.

.

Thus, the answer is conference