For This Pair of Items, Choose the Option That Best

For this pair of items, choose the option that best describes their relationship.
(A) The average size of particles that constitute silt
(B) The average size of particles that constitute clay

A) Item (A) is larger than item (B) .
B) Item (A) is smaller than item (B) .
C) Item (A) is exactly or very approximately equal to item (B) .
D) Item (A) bears no relationship to item (B) .