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, which were made from cloth nappies/diapers, as a visible, symbolic plea for the safe return or information about their missing children.

Answer:

a plea for their children.