In the spаce prоvided, write the letter оf the sentence thаt best expresses the implied mаin idea оf each of the following paragraphs. 1By the late 1800s, European scientists had identified three macronutrients considered essential in large quantities because they supply energy: proteins, carbohydrates, and fats. 2In fact, it was believed that these three macronutrients, together with certain minerals, were sufficient to sustain life in animals and humans. 3As a result, when an invading army cut off supplies of cow’s milk to Paris in 1870, some enterprising individuals manufactured artificial milk substitutes intended to keep infants alive. 4But after many children died of malnutrition, a French chemist began to suspect that small amounts of some additional substances—as yet unidentified—were also indispensable for survival. 5Then in 1897, a Dutch scientist noticed that chickens developed a disease called beriberi when they were fed only rice that had been “polished” by removing its outer layer, or “hull.” 6Believing the “germ theory” prevalent at the time, this scientist assumed that the disease was caused by a toxin that could be neutralized by the hull. 7A colleague came to a different conclusion: rice hull must contain a micronutrient—a substance necessary in tiny amounts for good health. 8Subsequently, a Polish biochemist identified those substances which—when absent—caused beriberi and other deficiency disorders. 9In 1911, he named these micronutrients “vitamins,” combining the words vita (the Latin word for “life”) with amine (an organic compound essential for life). A. The three essential nutrients are protein, fat, and carbohydrates. B. Whole grain rice is more nutritional than polished rice. C. The concept of nutrition was developed over two hundred years ago. D. By the early 1900s, scientists had discovered that both macronutrients and micronutrients are essential to health.