What is the sequence by which the anions below will precipitate out of solution as the concentration of lead(II)

Question

What is the sequence by which the anions below will precipitate out of solution as the concentration of lead(II)

ions is increased? (Ksp of: PbCrO4=2.8×10-13, PbSO4=6.3×10-7, PbF2=3.6×10-8)

a.PbSO4, PbCrO4, PbF2

b.PbCrO4, PbF2, PbSO4

c.PbCrO4, PbSO4, PbF2

d.PbF2, PbSO4, PbCrO4

Science