Only children older than... may ride on a motorcycle driven by their father, mother, or guardian, or by an adult authorized by them.

Correct answer: 7 years old.

7 years old. As a general rule, a motorcycle passenger must be 12, but from age 7, a child may ride if the rider is their father, mother, guardian, or an adult authorized by them. At age 5, no rider may carry the child.

Real Decreto Legislativo 6/2015, de 30 de octubre, por el que se aprueba el texto refundido de la Ley sobre Tráfico, Circulación de Vehículos a Motor y Seguridad Vial · Real Decreto 1428/2003, de 21 de noviembre, por el que se aprueba el Reglamento General de Circulación