Which of the following is the Hill equation, as applied to hemoglobin?

Question $7$ options:

log $[$theta$/(1-$ theta$)]=$ n log pO$2-$ log P$50$

theta $=$ log$[$S$]/$log$([$S$]+$ log$($P$50))$

log $[$theta$/(1-$ theta$)]=$ n log $[$S$]-$ n log K$0\mathrm{.}5$

log $[$theta$/(1-$ theta$)]=$ n log pO$2-$ log K$0\mathrm{.}5$

None of the above