In this sentence improvement question, choose the alternative that best improves the bracketed part of the sentence. If no improvement is needed, select "no improvement". Sentence: "As he tried harder, his steps slowed, his senses (was activated)."

Introduction / Context:
This question is about sentence improvement and subject verb agreement in English grammar. You are given the sentence "As he tried harder, his steps slowed, his senses (was activated)." and asked to choose the grammatically correct form of the bracketed part. The focus is on matching the verb correctly with the plural subject "senses" and maintaining the tense used in the rest of the sentence.

Given Data / Assumptions:

- Subject phrase: "his senses". - Current form in brackets: "was activated". - Earlier verbs in the sentence: "tried", "slowed", both in simple past. - Options: is activated, were activated, were activate, no improvement, had been activated.

Concept / Approach:
In English, the verb must agree in number with its subject. "Senses" is a plural noun, so it requires a plural verb form. In the simple past passive voice, the plural form is "were activated", not "was activated". Also, the rest of the sentence uses simple past, so we should keep the same tense for consistency. Therefore, the correct improvement is "were activated". Other options either break subject verb agreement or use a different tense that does not match the sentence context.

Step-by-Step Solution:

Verification / Alternative check:
Insert each option into the original sentence and read it aloud. "As he tried harder, his steps slowed, his senses were activated" sounds natural and maintains past tense narrative flow. "His senses was activated" clearly sounds wrong because singular and plural do not match. "His senses is activated" shifts to present tense, which is inconsistent. "His senses were activate" is obviously incorrect, and "had been activated" suggests that the activation occurred before another past action, which the sentence does not indicate. This confirms that "were activated" is the best choice.

Why Other Options Are Wrong:
Option A "is activated" uses present tense and singular verb, both incorrect for a plural subject in a past tense narrative. Option C "were activate" fails because activate is not in past participle form, making the passive structure ungrammatical. Option D "no improvement" would keep the incorrect "was activated", which does not agree with the plural subject. Option E "had been activated" changes the tense and implies a different time order, which the sentence does not require. Only "were activated" satisfies both agreement and tense consistency.

Common Pitfalls:
Students sometimes focus only on tense and forget to check subject number. When several clauses appear in one sentence, it is easy to overlook that "senses" is plural. Another pitfall is choosing a more complex tense such as past perfect, thinking it sounds more advanced, even when it is not needed. In grammar questions, simplicity and correctness are more important than complexity. Always check both number agreement and tense sequence before finalising your answer.

Final Answer:
The correct improvement is "were activated", so the sentence should read: "As he tried harder, his steps slowed, his senses were activated."