May a child under 10 years old travel in the front seats of a passenger car?

A)Yes, always.
B)Yes, if they are taller than 1.35 metres.Correct
Minors whose height is equal to or less than 1.35 m must occupy the rear seats of the vehicle, always using a restraint device approved according to their height and weight.

There are three exceptions in which minors who do not reach that height may travel in the front seat:

1. When the vehicle does not have rear seats.
2. When all the rear seats are already occupied by minors with the same physical conditions and, therefore, it is unfeasible to place all the required child seats at that time.
3. When it is not possible to install child restraint systems in those seats.
When the height of minors is greater than 1.35 m, they may occupy the front seat using the adult seat belt.