Which of the following is not a sea route?

The sea routes mentioned in the options are London-Moscow-Baghdad, London-Cape Town-Melbourne, New York-London-Rotterdam, and Sydney-Suez-London. The question is asking for the option that is not a sea route. Therefore, the correct answer is the option that does not include any sea routes. The first option, London-Moscow-Baghdad, does not include any sea routes. The other options all include travel by sea, either across the Atlantic, Indian or Mediterranean Oceans. Therefore, the answer is: London-Moscow-Baghdad.