Which of the Following Statements About the Rounding of Boulders

Which of the following statements about the rounding of boulders by chemical weathering is NOT true?

A) Chemical exfoliation, the weathering of rocks in concentric layers, occurs because chemical weathering attacks the outside of the rock before attacking the inside.
B) Rounding occurs because rock edges and corners offer more surface area than its planar faces.
C) The rounding of angular rocks by chemical weathering is termed spheroidal weathering.
D) Rounding occurs because the portions of a rock on the edges and corners are less stable than portions in the interior of the rock.