True, that's why its known as a ''complex trait'', which mean that is usually caused by a mutation in gene.
A) Effective observation, because he is watching the signals that she is giving off through her facial expressions and gestures.
Hope this helped!! :)
This would exclude Digestion, being a factor in efficiency. All of the others are correct, except for answer D.
Respiratory syncytial virus, whooping cough, pneumonia