Answer:
The question is incomplete without the reasons. But here is the question with the reasons.
On a trip to the Southwest, you and a friend collect some seeds from a piñon, which is a type of pine tree. Your friend also gathers a small bagful of soil from under the piñon tree. Back home, both of you plant your seeds in commercial sterilized potting soil, but your friend adds a spoonful of the collected dirt to each of her pots. Her seedlings do better than yours. Which of the following is the likeliest reason?
A)The soil from the Southwest probably contained fungi able to establish a mycorrhizal association with the seedlings' roots.
B)The soil from the Southwest probably contained nitrogen-fixing bacteria that colonized theseedlings' root nodules.
C)Pine seedlings are better adapted to the sandy soil of the Southwest than to commercialpotting mix.
D)The soil from the Southwest probably contained macronutrients missing from the potting mix.
A is THE BEST REASON
the soil from the Southwest probably contained fungi able to establish a mycorrhizal association with the seedlings' roots
