Please answer the following question: Read the article and select the best answer. Article: Babies understand what their mothers say, even when they speak a language their children have never heard before, scientists claim. The researchers found that one-year-olds reacted in exactly same way to their mothers' voices regardless of whether they were speaking English or Greek, showing what mothers have long known - that babies pick up on tone of voice rather than the words themselves. The researchers, from Cardiff University's School of Psychology, observed babies as they watched their mothers perform actions with toys using the English words "whoops" and "there". The scientists studied reactions from one-year-old babies to their mums' voices even when they were speaking both English and Greek, and keeping the same tone of voice. The academics found that babies reproduced the same reactions regardless of whether they knew the language. Study leader Dr Merideth Gattis of Cardiff University's School of Psychology says, "What this work showed was that children could have access to understanding simply through tone of voice. We did 'whoops' and 'there' in two languages and got exactly the same results." The research, published in the journal Cognitive Development, was conducted on 84 babies aged between 14 and 18 months, over the course of a year, with none of the babies having any previous exposure to Greek. Dr Gattis says that children respond to tone clues in their parents' voices from an early age. She says, "Tone of voice is a really useful signal of what someone is thinking. We never have direct access to other people's minds, except the signals in language that they give out." She says the study shows that it is less important what parents say than how they say it. Dr Gattis adds, "A child may ask if you like his / her drawing, for example. You might say yes, but if you don't sound enthusiastic, the meaning may not get across." Before children begin to speak, parents should use exaggerated tone when speaking to them. Question: According to the text, Dr. Gattis believes that _ . Options: A: we have no access to other people's minds B: babies can't understand what "yes" means C: parents should always sound enthusiastic D: how a parent speaks is more important than what he or she says
Answer:
D