Question

text 1
in separate studies, stephen meding and robert j. zasoski and
xinhua he and colleagues examined whether plants transfer nutrients
to one another using a common mycorrhizal network (cmn)—a lattice
of fungal strands in the soil. meding and zasoski excluded all
pathways other than the cmn by using barriers to keep the plants
root systems separate while allowing mycorrhizal strands through—a
crucial step he and colleagues study did not take.
text 2
meding and zasoski took the necessary precaution of separating the
plants root systems (thereby excluding root - to - root transmission).
however, any barrier used must allow the thread - like hyphae of a
cmn to pass through, and this permeability would also allow liquids
through. thus, the researchers experimental design cannot ensure
that any nutrient transfer observed can be attributed to a cmn and not
to some other pathway.
based on the texts, the author of text 1 and the author of text 2
would most likely agree with which statement?
a) the barriers used in meding and zasoskis study effectively
excluded root - to - root transmission of nutrients.
b) a barrier that is impervious to both roots and fungal strands is
necessary to evaluate nutrient transfer via a cmn.
c) excluding root - to - root transfer of nutrients between plants is
sufficient to ensure that any observed nutrient transfer must involve a
cmn.
d) he and colleagues study did not find convincing evidence of
nutrient transfer between individual plants.

Explanation:

Text 1 mentions that Meding and Zasoski excluded all root - to - root transmission of nutrients. Text 2 says Meding and Zasoski took the necessary precaution of separating the plants' root systems (thereby excluding root - to - root transmission). So both texts agree that any barrier used must allow the thread - like hyphae of a CMN to pass through, and this permeability would also allow liquids through. Thus, the researchers' experimental design cannot ensure that any nutrient transfer observed can be attributed to a CMN and not to some other pathway.

Answer:

A. The barriers used in Meding and Zasoski's study effectively excluded root - to - root transmission of nutrients.