What are the temperature and pressure for N.T.P. (Normal Temperature Pressure)?

• A. 0 C, 1 bar
• B. 273 C, 15 bar
• C. 288 K, 1 bar
• D. 273 K, 1 bar
• E. ?a) 0 C, 1 barb) 273 C, 15 barc) 288 K, 1 bard) 273 K, 1 bar