Consider the two following statements $A$ and $B$, and identify the correct choice given in the answers: $(A)$ Duddell's thermo galvanometer is suitable to measure direct current only. $(B)$ Thermopile can measure temperature differences of the order of $10^{-3} {}^{\circ}C$.

• A
  Both $A$ and $B$ are true
• B
  Both $A$ and $B$ are false
• C
  $A$ is true but $B$ is false
• D
  $A$ is false but $B$ is true