Which of the following statements is a valid form of deductive reasoning?

A. Typically women don't like to be asked how old they are; therefore, this question should be avoided when possible.

B. A scientific study showed that those suffering from sleep disorders experience lack of concentration; therefore, they should sleep more.

C. Hot dog vendors obtain the most sales on Independence Day; therefore, vendors would greatly benefit from an increase of the purchase price of hot dogs on that day.

D. All else being equal, consuming fewer calories will result in weight loss; therefore, someone that wants to lose weight should eat less food.