The best description of the cause of Shays’s Rebellion is:
The federal government did not pay the veterans the money they were owed.
Shays's Rebellion, which took place in 1786-1787, was largely driven by economic distress among rural farmers in Massachusetts, many of whom were war veterans. They faced high taxes and debts and felt that the government was not doing enough to address their financial struggles, leading to widespread discontent and ultimately rebellion against tax and economic policies.