Select the correct answer. In which prototyping technique, is a solid physical model of a part obtained directly from a 3D CAD drawing without the use of tooling? OA virtual prototyping OB. 3D printing O C. rapid prototyping OD. selective laser sintering​

An air compression refrigeration system is to have an air pressure of 100 psia in the brine tank and an allowable air temperature increase of 60°f for standard vapor compression cycle temperatures of 77 f entering the expansion cylinder and 14 f entering the compression cylinder, calculate the coefficient of performance a. 2.5 b 3.3 c. 4.0 d. 5.0