SAT Question b64e2c7f: Linear Inequalities answer and explanation with Desmos solution

Choice B is correct. It's given that monarch butterflies can fly only with a body temperature of at least $55.0\text{degrees Fahrenheit}\left({}^{\circ }\text{F}\right)$. Let $x$ represent the minimum increase needed in the monarch butterfly's body temperature to fly. If the monarch butterfly's body temperature is $51.3^{\circ }\text{F}$, the inequality $51.3+x\ge 55.0$ represents this situation. Subtracting $51.3$ from both sides of this inequality yields $x\ge 3.7$. Therefore, if the monarch butterfly's body temperature is $51.3^{\circ }\text{F}$, the minimum increase needed in its body temperature, in ${}^{\circ }\text{F}$, so that it can fly is $3.7$.