The British felt justified in imposing the Stamp Act on the colonists for several reasons. Here are the relevant factors from your list:
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Britain has spent money protecting colonists from the French: The British government believed that since they had spent considerable resources during the French and Indian War (1754-1763) to protect the American colonists from French expansion and Native American attacks, it was reasonable to expect the colonists to help pay for those costs through taxes.
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British citizens living in England faced increased taxes due to wars in the colonies: The British government argued that the cost of defending the colonies was considerable and that British citizens were already facing increased taxes to cover the expenses of imperial defense, so it was fair for the colonists to contribute as well.
While the other options you provided may contain some arguable points, the two selected above are the most widely recognized justifications claimed by the British government for the Stamp Act. The intention of the Stamp Act was primarily to raise revenue to help pay off debts incurred during the war and to finance the ongoing defense of the colonies.