What phrase translates to "A life jacket is required"?

The phrase "Es obligatorio el chaleco salvavidas" translates to "A life jacket is required." In this context, "es obligatorio" conveys that something is mandatory or required, which is essential for understanding safety regulations, particularly in environments involving water activities. The term "chaleco salvavidas" specifically refers to a life jacket.

The other choices do not pertain to the requirement of a life jacket: "Gira a la derecha" means "Turn to the right," which involves navigation directions; "Ten cuidado" translates to "Be careful," a general warning; and "¡Cuidado!" is an exclamation that means "Careful!" or "Watch out!" These do not convey the specific requirement for wearing a life jacket.