Which of the following is a difference between fungus and plants?
a. fungus have mitochondria, plants do not
b. fungus have cell walls made of cellulose plants do not.
c. fungus are heterotrophs, plants are autotrophs
d. fungus have motile sperm, plants do not

Fungus are heterotrophs and plants are autotrophs (they make photosyntesis), that's the diference between fungus and plants.

Explanation:

In option a, as you know that plants and funghi are  eukaryotic, they both have mitochondria.

Option b is wrong, because plants, they do have cell walls of cellulose.

Option d is totally wrong, fungus and either plants, they do not have motile sperm.