Which of these statements must be true if two different plants are members of the same species?
a) they have the same number of chromosomes as one another.
b) they both produce flowers and seeds at the same time of year. c) their leaf shapes and patterns appear to be exactly the same.
d) they can produce offspring plants that also produce fertile seed.

As it is given in the question that both the plant belongs to same species and according to biological species concept, a species can be defined as the largest group of organisms in which any two two individuals of the opposite sex breed to produce a fertile offspring.

According to this the correct answer is D) They can produce offspring plants that also produce fertile seed.  

D

Explanation:

They can produce offspring plants that also produce fertile seed.

showing a photograph would make this a hell of alot easier

plato users

given bodies of water

pacific / arctic / indian / southern

[ a ] the caribbean sea

[ b ] the northern ocean

[ c ] the atlantic ocean

[ d ] the barents sea

with this being the given answers