Read the four sentences below and identify the one that contains a grammatical error. If all sentences are grammatically correct, select 'All are correct' as your answer.

Select the option containing the sentence with the error.

Correct Answer: The annual film festival demonstrated how a major cultural exhibition should been organized with systematic coordination.

Detailed Explanation:
Let us analyze the grammatical structure of each sentence to identify any error:

1. "The annual film festival demonstrated how a major cultural exhibition should been organized with systematic coordination."
This sentence contains a grammatical error in the verb phrase "should been organized". Modal auxiliary verbs such as "should" must be followed by the base form of a verb (e.g., "should be") or by "have" followed by a past participle (e.g., "should have been"). Using "should been" directly is grammatically incorrect.
Correction: It should read either "should be organized" or "should have been organized".

2. "With the rise of social media platforms, the lives of celebrities became more transparent to the general public."
This sentence is grammatically correct. The prepositions, subject-verb agreement, and past tense usage ("became") are all proper.

3. "The global demographic trends indicate that the rate of urbanization will accelerate significantly over the coming decades."
This sentence is grammatically correct. The plural subject "trends" matches the verb "indicate", and the future tense expression "will accelerate" is used appropriately.

4. "The domestic equity market is monitored by the regulator with stringent insider trading restrictions."
This sentence is grammatically correct. The passive voice formulation "is monitored" correctly matches the singular subject "market".

Therefore, the sentence containing the grammatical error is the first option.