\textbf{166.} The temperature of a metal disk is increased by 250 degrees Celsius, and as a result its surface area increases by one percent. What is the linear thermal expansion coefficient of the metal in SI units?
\[
(1)\ 2\times10^{-5} \qquad (2)\ 4\times10^{-5} \qquad (3)\ 2\times10^{-6} \qquad (4)\ 4\times10^{-6}
\]