Which statement correctly distinguishes a convex lens from a concave lens for rays initially parallel to the optical axis?

A student is drawing an image formed by a thin lens and can clearly construct the $P$-ray and $M$-ray. Which statement is most accurate?

An object is placed $30$ cm in front of a converging lens with a focal length of $12$ $\text{cm}$. What is the image distance?

A converging lens has a focal length of $10$ $\text{cm}$. An object is $25$ $\text{cm}$ from the lens. What is the magnification?

A thin lens forms an upright image with positive magnification for a real object. Which conclusion is necessarily correct for a single-lens setup in this lesson?