Identify the true statement. Choose one: A. Isotopic dating can be used only in a closed system, where neither parent material nor daughter material has escaped. B. The "radiometric clock" starts when a radioactive mineral warms above its closure temperature. C. Carbon-14 dating is used to date anything that was once alive, regardless of age. D. Scientists can date any radioactive material back only three half-lives; after this, there's not enough parent material left to measure.

The correct answer is option D) Scientists can date any radioactive material back only three half-lives; after this, there's not enough parent material left to measure.

Explanation:

It is true that the exact date of a radioactive material which is known to be unstable cannot be precisely determined due to loss of parent material. The radiometric clock takes a while to swing into action because of high temperatures. It begins after a while when the closure temperature of a radioactive material drops to the barest minimum. At this point, Scientists can date any radioactive material back only three half-lives because most of  the parent material needed for the experiment will not remain.

the answer is learned

the dependant variable is spilled water

the independent is the heat