Correct option is C
Option (c) is the correct order of the given parts.
• Subject + main verb idea comes first: (d) “Hamlet is unable to take a decision”
• “decision” needs completion (decision on what?): (c) “on what to do”
• Then consequence is added: (b) “and this leads to”
• Final result comes at the end: (a) “his tragic end”
Correct sentence formed: Hamlet is unable to take a decision on what to do and this leads to his tragic end.