A system S receives heat continuously from an electrical heater of power 10 W. The temperature of S becomes constant at \[50{}^\circ C\]when the surrounding temperature is \[20{}^\circ C\]. After the heater is switched off; S cools from \[35.1{}^\circ C\] to \[34.9{}^\circ C\] in 1 minute. The heat capacity of S is

• A. \[100J/{}^\circ C\]
• B. \[300J/{}^\circ C\]
• C. \[750J/{}^\circ C\]
• D. \[1500J/{}^\circ C\]