Correct option is B
Epidural anesthesia causes sympathetic blockade → maternal hypotension → decreased uteroplacental perfusion → late decelerations. First management is IV fluids and lateral tilt to improve venous return.
Explanation of options: (a) ✘ Oxytocin increases contractions but worsens hypoxia; not first-line here. (b) ✔ Correct; left lateral tilt and fluid bolus restore perfusion and relieve FHR decelerations. (c) ✘ Magnesium sulfate is for eclampsia, not epidural-induced hypotension. (d) ✘ Frusemide worsens hypovolemia; not indicated here.