The Following Questions Refer to the Description and Figure Below

The following questions refer to the description and figure below.
The figure represents a cross section of the sea floor through a mid-ocean rift valley, with alternating patches of black and white indicating sea floor with reversed magnetic polarities. At the arrow labeled "I" (the rift valley) , the igneous rock of the sea floor is so young that it can be accurately dated using carbon-14 dating. At the arrow labeled "III," however, the igneous rock is about 1 million years old, and potassium-40 dating is typically used to date such rocks. NOTE: the dashed horizontal arrows indicate the direction of sea-floor spreading, away from the rift valley.
Figure 25.1
-Argon-40, the daughter isotope of potassium-40, is a gas. Elemental potassium has an atomic mass of about 39. If the submersible robot (which is equipped with a drill that is long enough to get to the igneous rock) ascends from depth too quickly, gases trapped within igneous rock may rapidly expand, fracture the rock, and escape from the sample before it can be dated aboard the floating research vessel. Rock samples can also absorb argon gas. Which of these techniques has the highest chance of providing inaccurate dates of igneous rocks distant from the rift valley, and what type of inaccuracy would it cause?

A) if the date of the rock is determined by comparing the ratio of potassium-40 to potassium-39, underestimation of age
B) if the submersible robot is retrieved from the sea floor at a very slow speed, overestimation of age
C) if the submersible robot is equipped with a decompression chamber for the samples, underestimation of age
D) if the submersible robot keeps the sample in a chamber of pure argon at high pressure, overestimation of age