Compute the product matrix using Strassen's matrix multiplication algorithm.
Given a11=1; a12=3;a21=5;a22=7
b11=8;b12=4;b21=6;b22=2

A. c11=20;c12=12;c21=100;c22=15

B. c11=22;c12=8;c21=90;c22=32

C. c11=15;c12=7;c21=80;c22=34

D. c11=26;c12=10;c21=82;c22=34

Answer: Option D