Question

the mothers of the plaza de mayo wore white head scarves as
a symbol of their demands.
a plea for their children.
a proclamation for war.
a symbol of peace.

Explanation:

The Mothers of the Plaza de Mayo were a group of Argentine women whose children were disappeared during the military dictatorship. They wore white headscarves (inspired by the cloths used to diaper babies) as a visible, emotional plea for information about and the safe return of their missing children.

Answer:

a plea for their children.