Which expression is equivalent to this expression? the sum from n is equal to 3 to 20 of open paren n close paren
A
the sum from n is equal to 3 to 20 of n squared plus the sum from n is equal to 3 to 20 of 1B
the sum from n is equal to 3 to 20 of n squared plus the sum from n is equal to 3 to 20 of nC
the sum from n is equal to 3 to 20 of n plus the sum from n is equal to 3 to 20 of n plus the sum from n is equal to 3 to 20 of 1D
the sum from n is equal to 3 to 20 of n plus the sum from n is equal to 3 to 20 of n plus 1