The correct option is D I, II, III and IV
The legal system is the skeleton of any Country. The sources of laws in India are numerous. Foremostly, the constitution which is the supreme law of the land and which paves way for other laws to be made. Parliament enacts legislation on a particular subject matter and so do State legislature which prevails in form of law. Customary practices which are old and accepted by people and is in force since time immemorial become usage which is recognized by law. The case decided by courts (superior courts) mostly on the points when there is the absence of any express law acquires the form of law as precedents in the country.