Based on the traits given for the new organism, we can analyze the information:
- The organism is autotrophic, which means it can produce its own food, typically through processes like photosynthesis.
- It has a true nucleus, indicating that it is a eukaryote (organisms with complex cells that have a nucleus).
- The presence of gametes suggests that it has a reproductive system involving sexual reproduction.
Given these traits, the conclusion that can be made about the organism is:
A. The organism is eukaryotic and multicellular.
While it is also possible for some unicellular eukaryotes to be autotrophic and have gametes, the combination of having all these characteristics typically points towards multicellular eukaryotic organisms (like plants) rather than unicellular ones. Thus, option A is the best fit.