What location on a glaciers marks the area where mass input at the surface equals mass output at the surface

Which of these fragmental sedimentary rocks would most likely form farthest from the land?

Why is the huronian supergroup rock formation particularly interesting to scientists? because it looks like a cross-section of a giant, stone encyclopedia because it formed during the period when oxygen began to accumulate in the atmosphere because it contains unusually large amounts of oxygen and sulfur because it dramatically altered the planet's development when it first formed

__ has (or have) been one of the most common pull factors of migration within the united statesa. lack of humanityb. gamblingc. seafoodd. well paying jobs