Final answer:
Assuming a half-life similar to that for other isotopes, the original sample most likely contained approximately 20 grams of calcium-37.
Step-by-step explanation:
To determine the original quantity of calcium-37 in the sample, we need to understand the concept of half-life, which is the time it takes for half of a radioactive substance to decay. In this case, we do not have the half-life of calcium-37 specifically, so we will assume a common exercise approximation similar to the provided reference values for other isotopes (which typically are in the order of milliseconds). If 10 grams remain after 700 milliseconds, and the half-life was close to that timespan, it indicates that the sample had 20 grams half a life ago. Since there are no specifics on the half-life of calcium-37 given, this assumption allows us to select from the provided options an approximate initial amount.