Which of the following is a common technique advertisers use to mislead consumers into using “fad diets” to achieve optimal health and fitness?

Promising rapid weight loss with many calories.

Explanation: A common technique used by advertisers to induce consumers to use “fad diets” to achieve optimal health and fitness is to promise that their products or equipment will ensure that consumers will lose weight quickly and with a lot of calories.

option c (nickel) is not found in earth's crust. the earth's crust basically contains eight (8) elements namely: oxygen, silicon, aluminum, iron, calcium, sodium, potassium and magnesium (listed in order of abundance).