Elf's expected return is $=12$ percent if all factors are equal to zero.

a$.$ State whether Elf's shares are likely to go up or down with an increase in world industrial production, crude oil prices, the slope of the term structure, the risk premium, or the euro.

b$.$ Given these parameters, what is the expected return on Elf stock in a year when each factor is $10$ percent higher than its expectation?

c$.$ If Elf stock falls by $12$ percent during th is period, by how much does Elf overor underperform its expectation given each of the factors was $10$ percent higher than its expectation during the period?