Look at the graph above the minimum y value is -7 at the point (-3,-7).
We are looking for the y = that goes even  lower!!

Above is answer choice (1).  You can see the minimum y value is -2 (not less than -7)

Above is answer choice (2).  You can see the minimum y value is -6 (not less than -7)

Above is answer choice (3).  Whoa this one goes low!! Lower than the y value of the given graph way up above

Above is answer choice (4).  This graph does not go very low — it doesn’t even pass through the x-axis as its minimum y value is 2.