If a geologist takes a rock and scratches it across a tile and it leaves a reddish brown color behind what physical property is he or she investigating? Cleavage
Luster
Fracture
Streak

by using  production possibilities graph.  opportunity costs are key expenses in financial matters and are utilized as a part of registering money saving advantage investigation of a venture. such expenses, be that as it may, are not recorded in the record books but rather are perceived in basic leadership by processing the money costs and their subsequent benefit or misfortune.

the answer is d.index