Why should investors and others be careful in interpreting partial$-$year reports for companies that use the natural business year for their fiscal year?

a$.$ The operations of the companies vary significantly throughout the fiscal year.

b$.$ Partial$-$year reports show only the highest points of a business.

c$.$ Partial$-$year reports show only the lowest points of a business.

d$.$ These reports are not used for the fiscal year reports.