Will you expect a positive, zero, or negative linear correlation between the two variables for each of

Question:

Will you expect a positive, zero, or negative linear correlation between the two variables for each of the following examples?
a. SAT scores and GPAs of students
b. Stress level and blood pressure of individuals
c. Amount of fertilizer used and yield of corn per acre
d. Ages and prices of houses
e. Heights of husbands and incomes of their wives