28.
Your Answer is
Correct Answer is J
Explanation
asking is the accompanying adverbial after the main clause, to save the plant is the purpose adverbial of a serious effort be made, there is no punctuation between them, and there is no comma between the prepositional phrase and its modified components, so J is correct .
Here is an omitted sentence: asking that a serious effort (should ) be made When expressing subjective wishes, suggestions, requirements, and orders, you need to use the subjunctive mood should do/be/not and should can omitted.