The value of negative square root of 7 can be determined by either using a calculator or even just solely thinking about it. If we think about, negative square root of 4 is -2 and negative square root of 9 is -3. Therefore, the answer is C. We can also use a calculator to confirm the answer. -√7 is approximately -2.65 and therefore is a value between -2 and -3 which is point C.