Question

forming extensive networks via mycorrhizal association—that is, a symbiotic relationship between plants and fungi—______
which choice completes the text so that it conforms to the conventions of standard english?
choose 1 answer:
a it is the entanglement of pine trees roots and the fungus tricholoma matsutakes fungal hyphae that makes nutrient transport possible.
b the transport of nutrients is possible through the entanglement of pine trees roots and the fungus tricholoma matsutakes fungal hyphae.
c nutrients can be transported through the entanglement of pine trees roots and the fungus tricholoma matsutakes fungal hyphae.
d pine trees and the fungus tricholoma matsutake can transport nutrients through their entangled tree roots and fungal hyphae.

Explanation:

The sentence starts with "Forming extensive networks via mycorrhizal association...", so the subject of the main clause should logically follow what is doing the forming. The subject of the underlined part should be the entity that forms the network, which is the interaction between pine trees and the fungus (their roots and hyphae). Option D has "pine trees and the fungus..." as the subject, which matches the logical subject of the introductory phrase. Let's check other options: A uses a cleft sentence with "it", which doesn't match the subject of the introductory phrase. B has "the transport of nutrients" as the subject, which is not what forms the network. C has "nutrients" as the subject, which is also incorrect. So D is the correct choice as it has the correct subject (pine trees and the fungus) that forms the network and makes nutrient transport possible through their entangled roots and hyphae.

Answer:

D. pine trees and the fungus Tricholoma matsutake can transport nutrients through their entangled tree roots and fungal hyphae.