A 5 year old boy suffering from Duchenne Muscular dystrophy and polymyositis has been fasting for 8 hrs and has to undergo tendon lengthening. Which anaesthesia should be used –
Inhalational anaesthetic is the method of choice in children for induction. Intravenous induction is used when induction with mask (inhalation) is contraindicated (full stomach) or if child comes in the operation theatre with intravenous line in situ.
Sevoflurane is inhalational agent of choice, but it is not provided in the options.
Halothane is the second choice inhalational agent and it is used for induction as well as for maintenance. Halothane is used in N2O & O2 mixture (like other inhalational agent). So, best answer of this question is option `d.' i.e. inhalational N2O, O2 & halothane.

Note - Some books have given option 'a' as the answer. Option a is not wrong, but amongst the provided options, option d is best. Option 'a' is also correct (but not the answer of this question) as intravenous induction can be used when induction by mask is contraindicated or child already has intravenous line before coming to OT. Propofol or thiopental are used for induction and then maintenance is done by halothane or isoflurane (in N2O + O2 mixture).
About option 'c'

Succinylcholine (scoline) is contraindicated in muscular dystrophy.
Induction by IV thiopentone & maintenance by N2O & halothene
Induction by IV propofol and maintenance by N2O & O2
Induction by IV scoline and maintenance by N2O & Halothane
Inhalation N2O, O2 & halothene