Choose the sentence with no spelling error.

They were iresponsible in performing their dutes.  They were irresponcible in perfroming their duties.  They were irresponsible in performing ther dutys. They were irresponsible in performing their duties.

They were irresponsible in performing their duties.

The sentence with no spelling error is: They were irresponsible in performing their duties. The other sentences have the following spelling errors: "Iresponsible" should be "irresponsible". "Perfroming" should be "performing". "Dutys" should be "duties".