Question 914123
The  radian measure   of a central angle of a circle is defined as the ratio of the length of the arc the angle subtends, {{{s}}}, divided by the radius of the circle, {{{r}}}

{{{theta=s/r}}}

given:

{{{s=15cm}}}, {{{r=7cm}}}

{{{theta=15cm/7cm}}}

{{{theta=2.142857142857143}}} round to three decimals 

{{{theta=2.143}}}

so, answer is B){{{2.143}}}