For any two matrices A and B, AB + BA is a possible matrix, then:

A, B are square matrices of same order

The correct answer is Option (2) → A, B are square matrices of same order

let order (A) = $a×b$

order (B) = $p×q$

if AB defined then $b=p$

BA defined then $a=q$ ⇒ $p×q=a×b$

as AB + BA defined

$⇒a×b=b×a$

$⇒a=b$

$(A, B)$ → square matrices of same order