If in *Δ*ABC, secA, secB, secC are in harmonic progression, then

(A) a, b, c, are in harmonic progression.

(B) cotA/2,cotB/2,cotC/2 are in harmonic progression

(C) r_{1},r_{2},r_{3} are in arithmetic progression

(D) cotA/2,cotB/2,cotC/2 are in arithmetic progression