Which of the Following Statements Is True of Percent Agreement

Which of the following statements is true of percent agreement as a measure of interrater reliability?

A) It can be extended to cases involving more than two observers by computing the agreement for each possible pair of observers and averaging the result.
B) It understates the true level of interrater agreement in those cases where behaviors occur with very high or low frequency.
C) It makes provisions for estimating the extent to which an agreement observed may have occurred by chance.
D) It was designed primarily for ordinal data and is inapplicable to nominal-scale data.