Convert the following Infix expression to Postfix form using a stack.x + y * z + (p * q + r) * s, Follow usual precedence rule and assume that the expression is legal.

• A. xyz*+pq*r+s*+
• B. xyz*+pq*r+s+*
• C. xyz+*pq*r+s*+
• D. xyzp+**qr+s*+