Parallel structure and natural phrasing (intensifier "so … that"): Check if the sentence needs correction. Original sentence: "The drama had many scenes which were so humorous that it was hardly possible to keep a straight face." Choose the best option.

Given data

• Structure: so + adjective + that + clause.
• Infinitival complement: "to keep a straight face" after "possible".

Concept/Approach
The original sentence already follows the idiomatic "so … that" pattern and correctly uses the infinitive after "possible".

Option analysis
E. "No correction required" → sentence is correct. ✔A/D → awkward/incorrect non-finite complements after "possible". ✖B/C → logical error ("hardly impossible") and wrong form. ✖

Final Answer
No correction required