No need to exaggerate. You'll be fine. You cut off the bottom of the question, which you might not want to do next time your life is in peril.
Here's how I'd do it; it's not A, B or C. Is it D or even E? We'll never know.
Let's label the top of what we'll call the lens T and the bottom U.
I'd calculate the two halfs of the lens separately, which is sliced into two pieces by the segment TU. Let's call the two pieces the Crescent L for left and Crescent R for right.
Their respective areas are each the difference of a circular sector (pie wedge) and an isosceles triangle.
Area(Cresent L) = Area(Sector BTU) - Area(Triangle BTU)
Area(Cresent R) = Area(Sector ATU) - Area(Triangle ATU)
So
Answer: Area(Lens) = Area(Sector BTU) + Area(Sector ATU)
- Area(Triangle BTU) - Area(Triangle ATU)
Like I said, not A, B or C.