What Would Be the Most Effective Way to Familiarize an Infant

What would be the most effective way to familiarize an infant with the head-turn preference for an experiment that investigates whether the child can differentiate between French and English words?

A) Allow the child to spend several minutes habituating to the experiment room while French and English words are presented at random from speakers in opposite corners of the room.
B) Allow the child to spend several minutes habituating to the experiment room while alternating red and green lights, but no sounds, are presented from opposite corners of the room.
C) Allow the child to spend several minutes habituating to the experiment room while a single light is presented simultaneously with a word in one or the other language from the same side of the room.
D) Allow the child to spend several minutes sitting silently on the parent's lap in the experiment room.