Step 1: Recall the goal of the Paris Agreement. This 2015 agreement was built around keeping global temperature rise under control compared to pre industrial times. Step 2: Remember the exact target. The text commits countries to holding the increase well below $2^\circ C$, while pushing efforts further to cap it at $1.5^\circ C$. Step 3: Pick the option that reflects the full range. Since the agreement gives a range rather than one fixed number, the correct choice is the one spanning $1.5^\circ C$ to $2^\circ C$. \[ \boxed{1.5^\circ C - 2^\circ C} \]