Answer:
B. Does the organism perform photosynthesis?
Step-by-step explanation:
Plants are autotrophic, that is they are capable of making their own food. They carry out photosynthesis, converting light energy to chemical energy which they use.
Fungi on the other hand are heterotrophic, they do not make their own food. They do not carry out photosynthesis.
Hence, ability to perform photosynthesis is an attribute that'll differentiate between fungi and plants.