Which of the following statements are correct about the scree plot of a principal component analysis?

I. A scree plot shows the fraction of total variance in a data set explained by each principal component.

II. The proportion of variance explained for the first few principal components has a magnitude higher than those of other principal components.

III. The higher proportion of variance explained is considered worthless.

IV. The scree plot criterion looks for the "elbow" in the curve and selects all components just before the line flattens out.

a.

Statements II, III, and IV only

b.

Statements I, II, III, and IV are all correct

c.

Statements I, II, and III only

d.

Statements I, III, and IV only

e.

Statements I, II, and IV only