Which of the following was a reason that the is senate refused to let the united states join the league of nations

You didn't provide choices, but the main reason for refusing entry into the League of Nations was the belief that doing so meant giving up some of the United States' own sovereignty and could commit the US to defend other nations' security rather than its own.

Context/detail:

The United States never joined the League of Nations, in spite of the fact that an organization such as the League of Nations was the signature idea of US President Woodrow Wilson.  He had laid out 14 Points for establishing and maintaining world peace following the Great War (World War I).  Point #14 was the establishment of an international peacekeeping association. The Treaty of Versailles adopted that idea, but back home in the United States, there was not support for involving America in any association that could diminish US sovereignty over its own affairs or involve the US again in wars beyond those pertinent to the United States' own national security.   Because of its objections to membership in the League of Nations, the United States Senate refused to ratify the Treaty of Versailles.

the underground railroad (apocope of the metropolitan railroad) is a system of urban trains located within a city and its metropolitan area. it is characterized for being a massive transport of passengers in the big cities, uniting diverse zones and their environs, with high capacity and frequency and in segregated form to other systems of transport. metropolitan railroads are built underground or on the surface, although most systems use mixed models where sections are combined in both modalities.

1 - as a result, the metro tends to reduce car travel for two reasons: first, due to the greater transfer of users from the car and, second, due to the reduction in the acquisition of cars in homes located in sectors near the stations of the metro.

2 -the metro allows to contribute effectively to the achievement of all the objectives of an urban development policy: it improves the efficiency of the city's economy by reducing travel costs and also generates a higher level of activities in the city center, taking advantage of of the agglomeration economies.

3 -it is a clean means of transport, since it uses renewable energy (usually electricity), taking care of the environment and avoiding excessive pollution.