A clock while keeps correct time at 30° C has a pendulum rod made of brass. The number of seconds it gains (or) looses per second when
the temperature falls to 100 C is [ a of brass= 18 × 10^-6 /°C ]

• A

  18 × 10^-6 sec

• B

  18 × 10^-5 sec

• C

  0.0018 sec

• D

  0.018 sec