A 26 year old primigravida with severe rheumatic heart disease(mitral stenosis with mitral regurgitation) is in early labour.The obstetrician wants to try a normal labour.Which of the following is the ideal intervention for labour analgesia ?

• A. Parenteral opioids
• B. Neuraxial analgesia
• C. Inhalational analgesia
• D. Spinal anaesthesia