In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Problem: the citizens of planet nigiet are 5 fingered and have thus developed their decimal system in base 8 . a certain street in nigiet contains 1000 ( in base 5 ) buildings numbered 1 to 1000 . how many 3 s are used in numbering these buildings ? express result in terms of base 10 .
Options: ['a ) 54', 'b ) 64', 'c ) 75', 'd ) 85', 'e ) 100']
c