DIRECTIONS: Read the passage given below and answer the questions that follow. Passage-2 The smallest time interval that can be measured with commonly available clocks and watches is one second. However now special clocks are available that can measure time intervals smaller than a second. Some of these can measure time intervals as small as one millionth or even one billionth of a second. Which of the following will be needed to measure the time period of a pendulum?

• A. a stop watch               
• B. a table clock
• C. a wrist watch  
• D. any one of these