The correct answer is "a warning."
is a noun that means: A warning or caution; admonition.Law:
A legal notice to a court or public officer to suspend a certain proceeding until the notifier is given a hearing:
a caveat filed against the probate of a will.
Latin: let him beware, 3rd person singular present subjunctive of cavēre to take care; see caution.
1540s, from Latin, literally "let him beware," 3rd person singular present subjunctive of cavere "to beware, take heed, watch, guard against," from PIE root *skeue- "to pay attention, perceive" (cf. Sanskrit kavih "wise, sage, seer, poet;" Lithuanian kavoti "tend, safeguard;" Armenian cucanem "I show;" Latin cautio "wariness;" Greek koein "to mark, perceive, hear," kydos "glory, fame," literally "that which is heard of;" Old Church Slavonic chujo "to feel, perceive, hear," cudo "wonder," literally "that which is heard of;" Czech (z)koumati "to perceive, be aware of;" Serbian chuvati "watch, heed;" Old English sceawian "to look at" (cf. show (v.)); Middle Dutch schoon "beautiful, bright," properly "showy;" Gothic hausjan "hear").