The rise or fall of head ' \(h\) ' in a capillary tube of diameter ' \(\mathrm{d}\) ' and liquid surface tension ' \(\sigma\) ' and specific weight ' \(w\) ' is equal to:

(a) \(\frac{4 \sigma}{w d}\)

(b) \(\frac{4 d \sigma}{w}\)

(c) \(\frac{4 w d}{\sigma}\)

(d) None of these