A$.$ Consider a firm that reads $x-$rays. It has two inputs, software programs and radiologist hours. Its outputs are x$-$ray based diagnoses. It has five alternative technologies it could use. To produce one x$-$ray based diagnosis, the requirements of each of these technologies is set forth in the table below:

$\backslash$table$[[$Technology$,$Software programs,Radiologist hours$],[$A$,6,1],[$B$,2,4],[$C$,7,3],[$D$,5,5],[$E$,1,10]]$

What technology dominates technology D$?$

$B-$ Continuing with this firm, suppose it is operating at technology $B.$ Then the price of software programs falls, and it switches to another technology. What is the new technology that it uses?