\(H_3 PO_4 \,\, ^{\underrightarrow{1}} H_4 P_2 O_7 \,\, ^{\underrightarrow{1}} HPO_3\) Indicate the temperatures 1and 2?

• A. 1.300°C 2.1000°C
• B. 1.250°C 2.900°C
• C. 1.250°C 2.500°C
• D. 1.100°C 2.1000°C