According to Spanish traffic regulations, is it legal to drive a vehicle while barefoot or wearing loose flip-flops?

A)No, there is a specific article in the traffic code that explicitly names and bans flip-flops, carrying an automatic fine of 200 euros.
B)Yes, it is completely legal, and traffic officers are legally prohibited from fining a driver based on their choice of footwear.
C)There is no direct ban, but you can be fined up to 200 euros if an officer determines that your footwear restricts your freedom of movement or prevents full control of the pedals.Correct
This captures the exact nuance of Spanish law (Articles 17.1 and 18.1). While the law doesn't explicitly mention the words "flip-flops" or "barefoot," it strictly dictates that a driver must maintain complete control of the vehicle and freedom of movement. If loose footwear or bare feet interfere with safely operating the pedals, an officer can issue a fine ranging from 80 to 200 euros.