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One of the most significant changes in the political landscape of seventeenth-century England occurs when

Athe monarchy is restored.
Bthe Pope appoints a new king.
Cthe Roundheads seize control of the army.
Dthe colonies secede from the British empire.

Verified Answer :

One of the most significant changes in the political landscape of seventeenth-century England occurs when "A. the monarchy is restored" since this took place in 1660 and brought a kind back to power.