Which of the following is australia's most important and well-known natural wonder

Sydney Harbour is one of the most well known natural wonders in Australia and quite possibly the most recognisable and beautiful harbour in the world. The Sydney Harbour stretches 20km inland and covers approximately 240 kilometres of shoreline; the area has a large number of beaches (including the iconic Bondi Beach) and inlets tucked away; there are also large sections of parklands, reserves and gardens. Sydney Harbour is home to the world famous Sydney Opera House and Sydney Harbour Bridge.

May consider a group  g=({0,1},+)g=({0,1},+)where  ++  will work as the xor operator like we work in boolean algebra. note here, that ‘00’ and ‘11’ are not the usual 0 and 1 that we work with everyday. the elements are  called  ‘00’ and ‘11’ and  may not mean  zero (nothing) and one (single). ‘00’ is the identity for the given binary operator +, meaning that any element operated with ‘00’ gets us that element itself.  for a set  ss  in  g′g′  having more elements than just  {0,1}{0,1}  the values for  a+b∈sa+b∈s, such that  a∈s,b∈sa∈s,b∈s, have to be first defined, only then can you determine the value of  1+11+1. the answer could possibly have been  22  if oanswer is25,000

Dall of the above all of the choices make sense