The most accurate comparison is:
Both fossils and trilobites are extremely old. However, a trilobite was a creature that was living on Earth at some point that over time turned into a fossil, meaning a trilobite is one type of many different types of creatures found in fossils.
This response correctly distinguishes between trilobites (which are ancient organisms that lived in the past) and fossils (which are the preserved remains or traces of various organisms, including trilobites). Furthermore, fossils encompass a wide range of organisms and are not limited to just trilobites.
The other responses contain inaccuracies, such as stating that fossils or trilobites are around 1,000 years old, and incorrect information about their locations.