In each of the questions given below, four sentences have been given. Out of four sentences, one sentence has an error. Find out which of the following sentence has an error. If all the given sentences are error-free then choose option ‘ All are correct’ as your answer choice.

Select the sentence that contains a grammatical error, or select 'All are correct' if every sentence is correct:

The correct answer is: "The volunteers labored throughout the week to constructed a sturdy shelter."

Explanation:

Let's examine the grammatical structure of the given sentences to identify the error:

1. "The volunteers labored throughout the week to constructed a sturdy shelter."
This sentence contains a grammatical error in the infinitive phrase "to constructed". The particle "to" expressing purpose must be followed by the base form (infinitive) of the verb, not its past tense or past participle form. Therefore, "to constructed" should be changed to "to construct".
Corrected version: "The volunteers labored throughout the week to construct a sturdy shelter."

2. Analysis of other options:
• "Individuals with strong communication skills can effortlessly persuade others." — Grammatically correct.
• "An ancient oak tree has recently turned into a popular gathering spot for neighborhood residents." — Grammatically correct.
• "Whispering a quick plea to the heavens, she immersed her feet into the stream and crossed the river." — Grammatically correct.