When the gametophyte is not formed by spores but by any other part of sporophyte, it is known as
apospory
The correct option is D.
Explanation of the correct option:
Explanation of the incorrect options:
Option A:
Option B:
No such phenomenon of multispory exists.
Option C:
Final answer: When the gametophyte is not formed by spores but by any other part of sporophyte, it is known as apospory.