$A$ calorie is defined as the amount of heat required to raise the temperature of $1 \, g$ of water by $1^{\circ} C$. Under which of the following conditions is this defined?

• A
  From $14.5^{\circ} C$ to $15.5^{\circ} C$ at $760 \, mm$ of $Hg$
• B
  From $98.5^{\circ} C$ to $99.5^{\circ} C$ at $760 \, mm$ of $Hg$
• C
  From $13.5^{\circ} C$ to $14.5^{\circ} C$ at $76 \, mm$ of $Hg$
• D
  From $3.5^{\circ} C$ to $4.5^{\circ} C$ at $76 \, mm$ of $Hg$