Drug A (with diffusivity in the tissue 1.0106cm2/s ) is to be delivered to the body from a surface patch, which keeps the tissue concentration of A at the tissue surface to be 2.0mol/m3. To be effective for a particular therapeutic purpose, the drug concentration needs to be 0.2mol/m3 at 5mm beneath the surface. You may ignore the curvature of the tissue or the patch, i.e. assume things are flat. (A) Assume the patch is applied to the thigh where the soft tissue is much thicker than 5mm. Draw the system. How long does it take for the drug to start taking effect (in hours)? Provide the equation(s) and boundary/initial condition(s). (17 pts) (B) Assume the patch is applied to the wrist area where the soft tissue is 5mm thick and underneath is bone tissue, which can be considered impermeable to the drug. Draw this system. How long does it take in this scenario for the drug to take effect (in hours)? Provide the equation(s) and boundary/initial condition(s). (18 pts)