New fax machines are to be purchased for the Ministry of Science and Technology. The type 1 fax machine costs Rs. m each and the type 2 fax machine Rs. n each. The type 1 needs "r" m2 of table space and the type 2 "s" m2. Total table space available is "t" m2. At least b of each type must be bought and the total budget must not exceed Rs. A. Which one of these options models the situation mathematically if x is the number of type 1 fax machine and y the number of type 2 fax machine?
Option
A. x = b, y =b xr + sy = t subject to mx + ny = A
B. x >b, y >b xr + sy < t subject to mx + ny = A
C. x = b, y =b xs + ry = t
subject to my + nx = A
D. x > b, y > b (x+y)(r+s)= t subject to (m+n)(r+s) = A