Improve the bracketed part of the sentence by choosing the correct option. If no improvement is required, select "No improvement". Sentence: Mixed cropping should be encouraged both as a (hedge for) price risk and for its ecological benefits.

Introduction / Context:
This sentence improvement question tests your knowledge of fixed prepositional collocations in English. The phrase hedge for price risk sounds slightly unnatural. You must identify the correct preposition that typically follows hedge when the verb or noun is used in the sense of protecting oneself against financial risk or uncertainty.

Given Data / Assumptions:

• The sentence is: Mixed cropping should be encouraged both as a hedge for price risk and for its ecological benefits.
• The bracketed part is hedge for.
• Options: hedge against, hedge of, hedge in, No improvement.
• We assume the intended meaning is that mixed cropping acts as a protection from price risk.

Concept / Approach:
In financial and general English, the fixed collocation is hedge against something, meaning to protect oneself from a possible loss or negative outcome. For example, farmers hedge against price fluctuations by diversifying crops. The preposition for is not usually used in this context. Hedge of refers to a physical hedge, hedge in means to restrict or surround, and No improvement would leave the non standard phrase hedge for unchanged. Therefore, hedge against is the correct improvement.

Step-by-Step Solution:
Step 1: Identify the underlying meaning of hedge here: a measure taken to reduce the risk of loss from price fluctuations.Step 2: Recall common phrases such as hedge against inflation and hedge against currency risk.Step 3: Note that these always use against as the preposition after hedge when discussing risk.Step 4: Replace hedge for with hedge against in the sentence and check: Mixed cropping should be encouraged both as a hedge against price risk and for its ecological benefits now sounds natural and idiomatic.Step 5: Verify that hedge of and hedge in do not convey protection from risk. Hedge of would simply describe a hedge surrounding something, and hedge in means to confine or restrict. Thus, hedge against is the only suitable choice.

Verification / Alternative check:
Try substituting each option into the sentence. Hedge for price risk feels awkward and is not the usual expression in economics. Hedge of price risk is ungrammatical. Hedge in price risk suggests confinement rather than protection. Hedge against price risk fits both economic writing and standard English, reflecting how risk management is normally described. This substitution test confirms hedge against as the correct answer.

Why Other Options Are Wrong:
Hedge of and hedge in fundamentally change the meaning from protecting against risk to describing physical surroundings or restriction. Leaving the phrase as hedge for does not match common usage and would likely be marked incorrect in a competitive exam that tests standard collocations. Because the question clearly focuses on the right preposition after hedge with risk, hedge against is the only acceptable option.

Common Pitfalls:
Many learners understand the general meaning of hedge but are uncertain about the specific preposition that should follow it. In English, risk related expressions often have fixed patterns: insure against, protect against, guard against, and similarly hedge against. Memorising these combinations through reading financial news articles can greatly improve accuracy in sentence improvement questions like this one.

Final Answer:
The correct phrase is hedge against price risk, so the bracketed part should be replaced with hedge against, making option A correct.