Error spotting: In the sentence "She has reduced her consumption to considerably", which underlined part contains the grammatical error?

Introduction / Context:
This error spotting question tests word order and the correct use of adverbs with verbs and objects. The sentence is meant to express that a person has greatly reduced how much she consumes. However, the phrase "to considerably" at the end is ungrammatical and does not form a correct expression in English.

Given Data / Assumptions:
- Full sentence divided into parts: She has (1) / reduced her (2) / consumption to considerably. (3) / No error (4). - The intended meaning: she has reduced her consumption by a considerable amount. - The problem lies in the last phrase involving the adverb "considerably".

Concept / Approach:
In English, adverbs like "considerably" usually modify verbs directly, as in "reduced considerably", or modify adjectives, as in "considerably lower". The preposition "to" cannot directly precede an adverb to express degree. The correct versions would be "reduced her consumption considerably" or "reduced her consumption to a considerable extent". Therefore, the error is in part 3, where "to" and "considerably" are wrongly combined.

Step-by-Step Solution:
Step 1: Read each part and see if it is grammatically correct on its own. Step 2: "She has" (1) is correct as a subject and auxiliary verb. Step 3: "reduced her" (2) is correct and naturally leads to an object. Step 4: "consumption to considerably" (3) sounds wrong. The verb "reduced" normally takes an object plus either a direct adverb (reduced consumption considerably) or a prepositional phrase with a noun (to a low level). Step 5: Recognise that "to considerably" is not a standard pattern in this context. Step 6: Therefore, part 3 contains the error.

Verification / Alternative check:
Recast the sentence in correct English: "She has reduced her consumption considerably" clearly expresses the intended meaning. Another natural version is "She has reduced her consumption to a considerable extent." Both avoid the incorrect "to considerably". Since the other parts of the original sentence are fine, the problem must lie in the third segment.

Why Other Options Are Wrong:
Part 1, "She has", correctly introduces the subject and auxiliary. Part 2, "reduced her", correctly begins the verb phrase and its object. Part 4, "No error", is just the answer label and does not belong to the sentence itself.

Common Pitfalls:
A frequent mistake is to place an adverb after "to" in an effort to express degree. Remember that "to" normally introduces a noun or noun phrase, not an adverb, after verbs like "reduce". When you want to use an adverb of degree, it usually goes directly after the verb phrase or before an adjective or another adverb.

Final Answer:
The error is in part (3); the phrase should not be "consumption to considerably".