How many different elements make up beryllium sulfite, beso3?

when ever there are captial letters in like an equation like this count all the ones that are capital and all of those that are capital are how many elements there is lets say this was an element WrTESd there would be 4 elements cause of the letters being capital thats a tip you can use it makes it really easy

i believe the answer would be:

d. violin, clarinet, french horn, and tuba

the answer is b, have negligible mass