The correct reactivity order of metals reacting with dilute HCl is option 1: Mg > Al > Zn > Fe.

Reactivity of metals is determined by their ability to lose electrons and form positive ions. In this case, the metals are reacting with dilute hydrochloric acid (HCl), which is a strong acid. When metals react with acid, they undergo a redox reaction where the metal atoms lose electrons and hydrogen ions (H+) are reduced to form hydrogen gas (H2).

Among the metals listed, magnesium (Mg) is the most reactive. It readily loses electrons to form Mg2+ ions, resulting in the production of hydrogen gas. Aluminum (Al) is less reactive than magnesium but more reactive than zinc (Zn). Iron (Fe) is the least reactive among the listed metals.

Hence, the correct reactivity order is Mg > Al > Zn > Fe. This means that magnesium will react most vigorously, followed by aluminum, zinc, and finally iron.

Alert - The correct answer should be option 2: Mg < Al < Zn < Fe.