Base Saturation (%) is calculated as:

Correct option is B

Base Saturation formula:

· Indicates soil fertility and pH status.
· High BS → more fertile soil; low → acidic soil.
· Found in Brady & Weil Soil Science.
Why other options are wrong
· (a) Inverse of correct.
· (c) Exchangeable acids not used for BS; used for AEC.
· (d) ESP only measures Na saturation, not BS.