(A) : If objective and eye lenses of a microscope are interchanged then it can work as 
telescope.
(R) : The objective of telescope has smaller focal 
length than its eye piece 

We cannot interchange the objective and eye lens of a microscope to make a telescope. The reason is that the focal length of lenses in microscope are very small. of the order of mm or a few cm and the difference $f_o-f_e$ is very small
 is very small, While the telescope length as compared to eye lens of microscope.