If A is a matrix of order m × 3, B is a matrix of order 3 × 2 and R is a matrix of order 5 × n such that AB = R, the values of m and n are :

1. m = -5 and n = -2

2. m = 5 and n = 2

3. m = 5 and n = -2

4. m = 2 and n = 5

A, B and C are three square matrices each of order 3; the order of matrix CA + B² is :

1. 3 × 1

2. 3 × 3

3. 1 × 3

4. 2 × 3