Interpret the bottom half of the cross section below. Start with the Vishnu Schist and end with the Redwall Limestone.

The vishnu schist is oldest that is 1.7 billion years old and the redwall schist is youngest.

Explanation:

The Vishnu schist is the exposed rocks of the grand canyon region they are formed at the basement region that underlines the base limestone. Which are followed by the Zoroaster granite which is an igneous-plutonic rocks intrusion and was later metamorphosed into gneiss.  Bass limestone a Mesoproterozoic rock that is found in the eastern grand canyon. The hakatai shale is a sedimentary rock formed by the mid deposits and seen in the formations of grand canyon varying in colors. The shinumo Quartzite is a sandstone rock of the eastern outcrop of the canyon. Dox sandstone,Tapeat sandstone are both resistant sandstone belts and are less prone to erosion and weathering. The bright angel shale is a soft greenish color sandstone rock and characterized as a cliff-forming resistant rock. The muav limestone is an upper geologic tonto group of rocks and has dolomite and calcareous deposits.  Red wall limestone is a high cliffed rock with an elevation of 500 to 800 feet. Is light olive grey and often thickly bedded sedimentary rock has crystalline dolomite.

Ibelieve the answer is c. map projections.hope my answer has you : )

Economy is the answer