Which of the following is most likely reason that the yad is used when reading the torah

[ou.01]which of these is the most likely use of an electromagnetic wave which has wavelength shorter than microwaves but longer than visible light? o heat food safely o neat food safely o take images of bones and teeth o transmit radio and cellular phone signals o take images of bones and teeth o transmit radio and cellular phone signals o detect the location of objects which emit heat

Can someone me? i need to have this done as soon as possible! i'm putting 20 points on this!

The blue segment below is a diameter of oo. what is the length of the radius of the circle?