Which of the following correctly states the SSS similarity criterion for two triangles?
(a) If two pairs of corresponding sides are proportional, the triangles are similar.
(b) If two angles of one triangle are equal to two angles of another triangle, the triangles are similar.
(c) If the three pairs of corresponding sides are proportional, the triangles are similar.
(d) If the three pairs of corresponding sides are equal, the triangles are similar.