The sentence needs two words that fit naturally with "come to ___ on interpreting the past" and "___ its national interests." Both blanks must work together to make the cause and effect of the sentence clear.
The correct option is consensus ... formulate, since it best links disagreement on history to the inability to build a clear national interest.
If the price of a commodity increases by 25%, by what percentage should the consumption be reduced to keep the expenditure the same?