Sticky wages and input prices can explain why profits change along a short run aggregate supply curve

Given the equations for C, I, G, and NX below, what is the marginal propensity to save?

C = 1,000 + 0.8Y I = 1,500 G =1,250 NX = 100 A) 0.2 B) 0.8 C) 1.8 D) 10

The trench warfare case during World War I is an example of a(n)

A) tit-for-tat strategy. B) explicit agreement. C) non-cooperative Nash equilibrium. D) None of the above.