Tonya and Mario are asked to use a pan balance to find the mass of the same rock. Tonya finds the rock's mass to be 680 grams. Mario finds the rock's mass to be 672 grams. Which is the best explanation for the difference in their measurements? A. Either Mario or Tonya measured the mass of the rock incorrectly on the pan balance.

B. The rock was cold when Tonya measured its mass and hot when Mario measured in mass.

C. The rock changed in size between the time Tonya measured it and the time Mario measured it.

D. The rock broke before Mario measured it. So the mass of the two pieces together was less than when Tonya measured it. PLEAS HELPPP

Submarines control how much they float or sink in the ocean by changing the volume of air and water contained in large ballast tanks. when the tanks are completely full of water, the submarine increases its overall mass and sinks down to the bottom. when the tanks are completely full of air, the submarine reduces its overall mass and floats to the surface. depending on the density of the seawater surrounding the submarine, it will pump seawater in or out of the tanks in order to achieve the same overall density as the sea water and float neutrally in the water. the volume of the submarine never changes. when the tanks are completely full of water, a submarine with a volume of 7.8\times10^3\text{ m}^37.8×10 3 m 3 7, point, 8, times, 10, start superscript, 3, end superscript, space, m, start superscript, 3, end superscript has a total mass of 8\times10^6\text{ kg}8×10 6 kg8, times, 10, start superscript, 6, end superscript, space, k, g. the density of the seawater is 10^3\text{ kg/m}^310 3 kg/m 3 10, start superscript, 3, end superscript, space, k, g, slash, m, start superscript, 3, end superscript. to make that submarine float neutrally, and neither float nor sink in the ocean, what volume of water does that submarine need to subtract from its tanks?