He applied his skill in engineering to toughen up the defence
Answer: production cost
Explanation: profit equals the total amount of money made minus the production cost. In financial terms, you have a profit when the amount of revenue gained from a business interaction surpasses its expenses as well as cost and taxes.
The correct answer is John Locke.
Enlightenment philosopher John Locke developed a theory of natural rights in which every free person had the rights of life, liberty, and property and that citizens entered into government to protect those rights.
Thomas Jefferson was heavily influenced by Locke and developed the concept of natural rights further writing in the Declaration of Independence that every citizen had the right to life, liberty, and the pursuit of happiness.