Question

Weather satellites are usually placed on:

north-south orbits
east-west orbits
oblique orbits
synchronous orbits

Answer 1

Weather satellites are usually placed on North-South orbits because this allows the satellites to see the entire surface of the Earth. 

Answer 2

It all depends on whose weather you want to watch.

-- Everybody's weather, all over the Earth ... north/south (polar) orbit

-- Close-up view of weather within a certain limited range
    of latitudes ... oblique orbit

-- Very limited range of latitudes, close to the equator ... low east/west orbit

-- Daily coverage of the same north/south strip ... synchronous oblique orbit

-- Continuous 24/7 view of the same area ... synchronous stationary orbit