Irina asked five of her students how many of the five of them had studied the day before.

Pol said none, Berta said only one, Ona said exactly two, Eugeni said exactly three and Gerard said exactly four.

Irina knew that those students who had not studied were not telling the truth, but those who had studied were telling the truth.

How many of these students had studied the day before?

\( 0\)\( 1\)\( 2\)\( 3\)\( 4\)