Which political development greatly increased tensions between the american colonies and great britain in the years just before the american revolution?
a) jay's treaty b) the xyz affair c) pinckney's treaty d) the proclamation of 1763

I believe the correct answer is D. the Proclamation of 1763.
This proclamation was issued by the British king and said that the Americans who fought for Britain against France would get nothing for their sacrifices in the war. This heightened the tensions because the relationship between two sides was already weak, and it grew even worse at this point.