Question 20 (1 point) If the radius r of a spreading circular rash is increasing at a rate of 0.7 cm/day, then the area A = 172 of the rash increases at a rate of ......... cm2/day when the radius of the rash is 2 cm. Note: ris a function of t (time) ( a) 2.8n O b) 4.27 O c) 5. 671 13 O d) 7n O e) None of the above