How would one describe a task that is "arduous"?

Describing a task as "arduous" implies that it is challenging and requires significant effort and endurance to complete. The term is often associated with strenuous or taxing activities that may involve physical labor or extensive mental effort. Thus, characterizing a task as difficult to accomplish accurately captures the essence of "arduous," as it conveys the notion that the undertaking is not only hard but may also be burdensome.

The other options suggest a lack of difficulty, with terms like enjoyable, pleasing, simple, and straightforward, which are fundamentally opposite to the concept of something being arduous. Therefore, the answer pinpointing the task as difficult to accomplish is the most fitting choice, as it directly aligns with the definition of the word "arduous."