$(1)$ We've all probably seen organizations that function in rundown buildings, yet morale and productivity are high.

$(2)$ One researcher $($Herzberg$)$ contends that people's attitudes toward their jobs far outweigh the importance of working conditions or environment. $(3)$ Herzberg has provided a list of motivational factors, or satisfiers, that can be said to motivate individuals and to produce job satisfaction.

$(4)$ Achievement is important to many employees. $(5)$ Is it to you? $(6)$ Achievement means feeling that you've accomplished a goal; that is$,$ you've finished something that you've started.

$(7)$ Some work situations provide this feeling; others, such as assembly$-$line work, often make feelings of achievement difficult. $(8)$ This is especially true when cycle times $($the time needed to complete one task$)$ are as short as $6$ seconds or less. $(9)$ One former student working for a food company that prepared institutional meals had a job that repeated every $2$ seconds. $(10)$ His task was to place two slices of white bread on a tray as it passed by on a conveyor belt $($later$,$ others added meat, condiments, etc., to produce a sandwich$).(11)$ Thirty times a minute the same task was performed, and he never saw the finished product. $(12)$ Not much of a sense of achievement there.

$3.$ Which sentence contains the central idea in paragraph $2($sentences $4-12)?$

a$.4$

b$.6$

c$.7$

d$.11$