According to the food and nutrition board (fnb) of the national academy of sciences, of calories should come from carbohydrates.

According to the food and nutrition board (fnb) of the national academy of sciences, 45% to 65% of calories should come from carbohydrates.

The diet should contain all the necessary components of diet in proper amounts. The processes of human physiology require chemical energy which is supplied by proteins, carbohydrates, lipids, vitamins and minerals. The main source of calcium is found in the  dairy products. Carbohydrates can be found in a variety of foods such as grains, legumes, nuts, fruits, milk, vegetables,  yogurt, and seeds.

Adults should obtain 45% to 65% of the calorie requirement from carbohydrates, 20% to 35% from fats and 10 to 35% from the proteins. The acceptable range for children are similar to the adults except that infants and younger children need a little higher amount of fat  around 25 -40 %.

c. earths continental crust is thicker than its lithosphere.

because, the lithosphere is the outermost layer of the earth/ 100 km thick and is defined by its machanical properties.the lithosphere contains oceanic and continental crust that varies in age and thickness across locations and geologic time. the lithosphere is the coolest layer of the earth in terms of temperature. the term lithosphere should not be confused with the use of "geosphere" which is used to indicate all of earth systems, including the atmosphere, hydrosphere   and biosphere. the surface of the earth can be divided into the continental crust and the oceanic crust.   the continental crust is made mostly of granite while the oceanic crust is made of basalt. the average thickness of the continental crust is 25 miles and the average thickness of the oceanic crust is 5 miles.   three types of rock, igneous, sedimentary, and metamorphic, make up the surface of the earth. that's why 3 option is preferable.