I would go with A.

By analyzing the garbage of a large number of average-sized households, a group of modern urban anthropologists has found that a household discards less food the more standardized—made up of canned and prepackaged foods—its diet is. The more standardized a household’s diet is, however, the greater the quantities of fresh produce the household throws away.
Which of the following can be properly inferred from the passage?
(A) An increasing number of households rely on a highly standardized diet.
(B) The less standardized a household’s diet is, the more nonfood waste the household discards.
(C) The less standardized a household’s diet is, the smaller is the proportion of fresh produce in the household’s food waste.
(D) The less standardized a household’s diet is, the more canned and prepackaged foods the household discards as waste.
(E) The more fresh produce a household buys, the more fresh produce it throws away.

the stem says:

P1 - modern urban anthropologists anaylzed large number of houses
P2 - standardized diet (x) = less canned food thrown away (y)
P3 - more standardized diet (a) = large quantities of fresh produce thrown away (c)

options

A - this is correct
B - less standardized diet (not a) = more non-food waste (d)
C - less standardized diet (not a) = small proportion of fresh produce thrown away (not c)
D - less standardized diet (not x) = more canned food thrown away (not y)
E - out of scope

Stimulus states that standardized= made up of canned and prepackaged foods. Therefore, more standardized means made up of more of canned and prepackaged foods. Nowhere in the stimulus does the author states that amount of canned and prepackaged foods the household discards as waste depends on the diet. Therefore D cannot be inferred.
On the other hand answer choice C represents the premise (both parts are negated) in the last sentence of the stimulus.
Hope that helps.

Premise 1: the more standard canned food they consume the less food they throw as garbage
Premise 1: The more standardized canned food they eat, the greater the quantities of fresh produce the household throws away.

(A) An increasing number of households rely on a highly standardized diet. OUT OF SCOPE AND UNSTATED FACT
(B) The less standardized a household’s diet is, the more nonfood waste the household discards. UNSTATED FACT, nowhere there is mentioning of non food trash
(C) The less standardized a household’s diet is, the smaller is the proportion of fresh produce in the household’s food waste. The inverse statement of premise 1, thus it is the correct answer.
(D) The less standardized a household’s diet is, the more canned and prepackaged foods the household discards as waste.UNSTATED FACT, not based on the premises. DOES NOT MAKE ANY SENSE. IF U DO NOT CONSUME CANNED FOOD, how could you dispose it in greater quantity. ARE U BUYIN it from the store and directly throwing into the trash????
(E) The more fresh produce a household buys, the more fresh produce it throws away. ANOTHER NONSENSE UNSTATED FACT.
Hope that helps.
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