This question has Statement $1$ and Statement $2.$ Of the four choices given after the Statements,choose the one that best describes the two Statements.
Statement $1:$ In an adiabatic process,the change in internal energy of a gas is equal to the work done on/by the gas in the process.
Statement $2:$ The temperature of a gas remains constant in an adiabatic process.

• A
  Statement $1$ is true,Statement $2$ is true,Statement $2$ is a correct explanation of Statement $1.$
• B
  Statement $1$ is true,Statement $2$ is false.
• C
  Statement $1$ is false,Statement $2$ is true.
• D
  Statement $1$ is false,Statement $2$ is false.