Given the task definition and input, reply with output. In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Problem: in how many ways can 5 different rings be worn in 4 particular fingers ? ( some fingers may get more than one ring and some may get no rings . ) can somebody explain ?
Options: a ) 6720 , b ) 7720 , c ) 7820 , d ) 7950 , e ) 8120
a