In the matrix multiplication, which one is correct? Note that r, s, t, u, P_i (i=1,2, , 7) are defined as follows:

r=ae+bg

s=af+bh

t=ce+dg

u=cf+dh

A.	r= P5 + P4 P2+ P6
B.	t= P3 - P4+ P6
C.	u= P5 - P1 P3 + P7
D.	None of the above.

P2= (a + b) . h P3= (c + d) . e P5 (a d) (e+ h) P6 (b - d) (g + h) P,= (a-c).(e+f)