To answer this question, we need to understand the reproductive behavior of each bird species mentioned.
Option A) Partridge and ostrich - This option is correct because both partridges and ostriches lay eggs on the ground. Partridges are ground-nesting birds that typically lay their eggs in a shallow nest on the ground. Similarly, ostriches are known for their large eggs that are laid in a simple scrape on the ground.
Option B) Partridge and crow - This option is incorrect because crows do not lay their eggs on the ground. Crows are known to build their nests in trees or other elevated structures.
Option C) Ostrich and crow - This option is incorrect for the same reason mentioned above. Crows do not lay their eggs on the ground.
Option D) None of these - This option is incorrect because partridges and ostriches both lay their eggs on the ground.
Therefore, the correct answer is A) A & B. Partridges and ostriches are the bird species that lay eggs on the ground.