Which of the phrases given below the sentence should replace the phrase printed in bold type to make it grammatically correct? If the sentence is correct as it is, mark 'E' as the answer.
They should have calmly thought of the advantages that would accrue to them.
should have been calm in thinking about
should be calmly thought of
shall have to calmly thought of
should have calmly think of
No correction required
Correct answer is E
No explanation has been provided for this answer.